
Class. KC:-^L 

Book JiW2i_: 

Copyright}) 

COPYRIGHT DEPOSTT. 



THE TECHNICAL PROCEDURES 



IN 



FILLING TEETH. 



BY 



G. V. BLACK, M.D., D.D.S., Sc.D., LL.D. 

Professor of Operative Dentistry 

in 

Northwestern University Dental School, 

and 

Dean of the Faculty. 



CHICAGO: 

THE BLAKELY PRINTING CO., PRINTERS AND BINDERS. 
I903. 



the library of 

: : ■ . - ess 

1 *o Copies - r 

OCT 17 903 

Copyright tnti» 



class 



N« 



COPY 3 



' ' 3 
XXc. 



■R 



Entered, according to Act of Congress, in the year 1903, by 

Greene V. Black, Chicago, III., 

In the Office of the Librarian of Congress, at Washington, D. C. 



PREFACE. 



This book is printed for the students of Northwestern 
University Dental School, and is intended to fill an imme- 
diate and pressing want in the particular field to which it 
is devoted — the technical procedures in filling teeth. It 
consists of a revision of my lectures of last year on that 
subject. The reprinting of these was not thought of until 
after the beginning of the school term of this year and the 
need of it had become especially manifest. The revision 
has therefore been done very hastily. The book is 
intended to answer a temporary purpose only; or until a 
more complete work can be prepared. 

The absence of illustrations in the book is well sup- 
plied in the school work by drawings, blackboard illustra- 
tions and lantern slides. Without these much of the 
matter would be difficult to understand by those unfamiliar 
with the methods of instruction employed in the school ; 
but with them, as employed, the need of them in the book 
is reduced to the minimum. The book is intended for 
the students of the school, not for the general profession. 

G. V. B. 
REPRINT. 

This reprint has been made necessary by the exhaus- 
tion of the previous issue. Corrections of a few errors 
have been made, some betterments of the text and some 
additions regarding porcelain inlays. G. V. B. 



THE TECHNICAL PROCEDURES IN FILLING 
TEETH. 



Introduction. 



Under the term Operative Dentistry we include all 
those operations upon the natural teeth and soft parts im- 
mediately connected with them that are usually performed 
by the dentist. But for convenience in teaching, and by 
common consent, certain operations are consigned to other 
departments. The extraction of teeth belongs to Oral 
Surgery; the preparation of natural teeth, or their roots, 
for crowns and bridges, belongs to crown and bridge work ; 
the regulation of irregular teeth to Orthodontia, etc., until 
to-day operative dentistry is pretty strictly confined to 
those operations upon the natural teeth and soft parts 
immediately connected with them for the repair of damage 
inflicted by caries, to prevent further caries, and the treat- 
ment of diseases resulting from exposure or death of the 
pulps of the teeth. To this is added that group of diseases 
of the peridental membrane beginning at the gingival 
border. 

The subject matter in this book will be confined to a 
brief presentation of the technical procedures in filling 
teeth. No study of pathological conditions will be under- 
taken ; not even of dental caries, further than a study of 
the position and forms of cavities, and such observations 
as may be necessary in the explanation of technical pro- 
cedures in the preparation of cavities and in filling teeth. 
The nomenclature relating to cavities and cavity prepara- 
tion, instruments and instrumentation, will be fully pre- 
sented. 

Nomenclature. 

Nomenclature treats of systems of naming things. 
Dental nomenclature treats of the terms, or names, used in 
dentistry. The subject is of first importance, for if we do 
not know the names by which things are called we will be 
unable to understand each other in speaking of them. 
Every profession, business or trade has its special system 



O THE TECHNICAL PROCEDURES IN FILLING TEETH. 

of naming things pertaining to it. and this nomenclature 
must be understood before the student can become pro- 
ficient. In operative dentistry this system of nomenclature 
is very simple and comprises but few words. However, 
these words are used in a fairly wide range of combina- 
tions that will be very perplexing to the student who has 
not a good knowledge of them. Every student should 
know them perfectly in their whole range of application 
before he leaves the junior class. He should understand 
them when spoken by others, and be able to use them 
freely and correctly in his ordinary speech. Otherwise 
he will be unable to understand his professors or fellow- 
students as accurately as he should, and thus find his 
studies more difficult than they otherwise would be. 

For the most part the words are the same as those used 
in Dental Anatomy, with which the student should be 
already familiar. But they are applied differently, and to 
different subjects. This new use now becomes a subject 
of study as applied in cavity preparation and cavity nomen- 
clature. 

Cavity Preparation. 

Cavity preparation includes all those operations re- 
quired in the removal of carious material from cavities 
formed in the teeth by decay, forming the cavities for the 
reception of fillings, and such extensions and preparations 
as will best fit the affected surfaces of the teeth to resist 
decay in future. 

Cavity Nomenclature. 

Rule: Cavities in the teeth take the names of the 
surfaces of the teeth in which they occur. 

"We group cavities together according as the decayed 
surfaces are similarly situated. A further grouping may 
also be made into classes, each class including those cavi- 
ties that require similar treatment. 

Cavities which occur in the occlusal surfaces of the 
teeth are called occlusal cavities, and occur in the molars 
and bicuspids, constituting a group. 

Cavities occurring in the buccal surface? of the bicus- 
pids and molars are called buccal cavities, and constitute a 
group. 



NOMENCLATURE. 7 

Cavities occurring in the lingual surfaces of the bicus- 
pids and molars are called lingual cavities. They are not 
frequent. 

Cavities occurring in the proximate, or proximal, sur- 
faces of the teeth are called proximate, or proximal, cavi- 
ties. These are divided into two groups, those occurring in 
the bicuspids and molars forming one group, bicuspid and 
molar proximal cavities, and those occurring in the incisors 
and cuspids forming a separate group, incisor proximal 
cavities ; the forms of the proximal surfaces of these two 
groups of teeth are so different as to require differences in 
consideration and treatment. Each of these groups is 
again subdivided into mesial cavities and distal cavities. 

Mesial cavities are those that are in surfaces of the 
teeth toward the median line as we follow the curve of 
the arch. 

Distal cavities are those that are in the surfaces of the 
teeth furthest from the median line, following the curve of 
the arch. 

Cavities occurring in the lingual surfaces of the upper 
incisors are considered as a separate group, incisor lingual 
cavities. Cavities occurring in the labial surfaces of the 
incisors and cuspids are called labial cavities. In each of 
these groups the individual cavity name is rendered specific 
by adding the name of the tooth in which it occurs, as: 
Occlusal cavity in the upper first molar, mesial cavity in 
the right upper central incisor, etc. We use proximal, or 
proximate, cavity only as a general term, always using 
mesial or distal when speaking of any particular proximal 
cavity. 

In addition to these terms, all cavities which occur in 
the axial surfaces of the teeth are called axial surface cavi- 
ties. These include all buccal, or labial, lingual and proxi- 
mal cavities. 

In each of these localities decay has peculiarities in its 
mode of attack, or there are differences of approach and of 
instrumentation in their preparation for rilling that render 
differences in their consideration necessary. 

Cavities are also divided into two groups, pit and fissure 
cavities forming one group, and smooth-surface cavities 



8 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

forming a second group. This constitutes a most important 
division of cavities of decay, calling for a radical distinc- 
tion in consideration and treatment. The pit and fissure 
cavities have their beginning in minute faults in the enamel 
of the teeth known as pits, formed where three or more 
lobes of the teeth join, making imperfect closure of the 
enamel plates, as upon occlusal surfaces of the bicuspids 
and molars and the lingual surfaces of the incisors, or at 
the endings of grooves, as upon the buccal surfaces of the 
molars. Fissure cavities begin in points of imperfect clos- 
ure of the enamel plates along the lines of the grooves. 
These latter may occur along the lines of the grooves of 
any of the teeth, but are seen mostly in the occlusal sur- 
faces of the bicuspids and molars. 

Smooth-surface cavities are those that begin in surfaces 
cf the teeth that are without pits, fissures, or faults of the 
enamel, i. e., in perfectly smooth surfaces. These positions 
are all on the axial surfaces, and in such positions that the 
surfaces are habitually unclean, either because of the posi- 
tion in relation to the motions of food in chewing, or the 
proximation of the surfaces of other teeth, as upon the 
proximal surfaces. Decay is the result of fermentation in 
these positions with the formation of an acid which dis- 
solves the lime salts of the teeth. 

Among the groups of cavities all of the occlusal cavities 
in the bicuspids and molars are, in their beginning, pit or 
fissure cavities. A part of the buccal cavities in the molars 
are pit or fissure cavities occurring in the buccal pits or 
fissured grooves, and part are smooth-surface cavities, oc- 
curring in the smooth portion of the enamel of this surface 
to the gingival of the pit, or in the gingival third. All 
buccal cavities in the bicuspids are smooth-surface cavities. 
All labial cavities in the incisors and cuspids are smooth- 
surface cavities. All lingual cavities in the upper incisors 
are pit or fissure cavities, and a few fissure cavities occur 
in the occlusal half of the lingual surfaces of the molars. 
All proximate, or mesial and distal cavities, whether in 
the molars, bicuspids or incisors, are smooth-surface cavi- 
ties. Lingual cavities in the gingival half of the molars are 
also smooth-surface cavities. 



NOMENCLATURE. 9 

Pit and fissure cavities occur in surfaces of the teeth that 
are habitually clean, except as the imperfections of the 
enamel — pits and fissures — afford places for the lodgment 
and fermentation of debris, which causes the beginning of 
decay. Therefore, in their preparation for filling they 
require no extension for prevention of recurrence of decay, 
further than a sufficient opening of the cavity to completely 
uncover the carious area and to find margins sufficiently 
level and smooth to allow of a good finish of the margins 
of the filling. Smooth-surface cavities occur in positions 
in which the surface of the enamel is habitually unclean, 
and usually begin in the central portion of the unclean area. 
The injury to the enamel surface tends to spread super- 
ficially from the central area of first beginning toward the 
margins of the unclean area. Therefore, such cavities 
require such extension in their preparation for filling as 
will include the habitually unclean area within their out- 
line in order to prevent the recurrence of caries. 

Classification of Cavities or Artificial Groups. 

In a classification of cavities it is the intention to group 
together in classes cavities of decay that require a similar 
line of treatment in order that these may be more closely 
associated. 

Class i. — Cavities beginning in structural defects in 
ine teeth, as pits and fissures. 

Class 2. — Cavities in the gingival third — not pit cavities 
—of the labial, buccal or lingual surfaces of the teeth. 

Class 3. — Cavities in the proximate surfaces of the 
incisors and cuspids which do not involve the removal and 
restoration of the mesial or distal angle. 

Class 4. — Cavities in the proximate surfaces of the 
incisors and cuspids which do require the removal and 
restoration of the mesial or distal angle. 

Class 5. — Cavities in the proximate surfaces of the 
bicuspids and molars. 

Class i. — Pit and fissure cavities. These cavities are 
located in the occlusal surfaces of the bicuspids and molars, 
in the occlusal two-thirds of the buccal surfaces of the 
molars, in the lingual surfaces of the upper incisors, and 



IO THE TECHNICAL PROCEDURES IN FILLING TEETH. 

occasionally in the lingual surfaces of the upper molars. 
They are all pit or fissure cavities. They occur in sur- 
faces of the teeth that are habitually clean, except as imper- 
fections of the enamel in the form of pits or fissures afford 
an opportunity for the lodgment and fermentation of debris 
which causes the beginning of decay. Therefore, the 
enamel surface immediately about the cavity being habit- 
ually clean, none of them require extension for the preven- 
tion of the recurrence of decay in their preparation for 
filling. All that is required is. to remove sufficient enamel 
to completely uncover the carious area and to obtain 
margins sufficiently level and smooth to give opportunity 
for a perfect finish of the filling. 

Classes 2, 3, 4 and 5 are all smooth-surface cavities. 
They all occur in positions in which the surfaces of the 
teeth are unclean habitually, and usually have their begin- 
nings in the central portion of the unclean area, with a 
tendency of the carious action to spread superficially upon 
the enamel surface. They, therefore, all agree in requir- 
ing extension for the prevention of the recurrence of decay 
in such a way as to include within the lines of the enamel 
margins of the prepared cavity all of that portion of the 
surface especially liable to decay. 

With respect to manipulative procedures, each of these 
classes has its especial peculiarities. For instance, Class 2, 
which includes all buccal, labial and lingual cavities, 
requires in most cases the use of the Hatch clamp on the 
incisors and bicuspids, and the special clamps on the molars 
to extend the rubber dam sufficiently to the gingival, and 
the method of instrumentation in their preparation is 
peculiar to them. 

Classes 3, 4 and 5 all agree in requiring the use of the 
separator to give room for finishing, because all are proxi- 
mate cavities, but each of these classes presents especial 
peculiarities in manipulative procedure which will receive 
attention later. 

Nomenclature of the Internal Parts of Cavities. 

In giving the nomenclature of the internal parts of cav- 
ities, the rules, and illustrations of each rule, will be given. 
Students should not burden themselves with memorizing 



NOMENCLATURE. II 

these illustrations, or lists, for if they know the rules and 
their application they can make complete lists at any time. 
This should be' practiced until the walls and angles of any 
cavity can be named at sight without hesitation. 

Rule: The surrounding walls of a cavity take the 
names of those surfaces of the teeth adjoining the surface 
decayed toward which they are placed. 
Illustration : Occlusal cavities have — 

A mesial wall, 

A buccal wall, 

A distal wall, 

A lingual wall, 
And— 

A fifth wall, which is called the pulpal wall, or floor 
of the cavity. 

Rule: That wall of a cavity which is to the occlusal 
of the pulp and in a plane at right angles to the long axis 
of the tooth, is called the pulpal wall or floor. In case the 
pulp of the tooth is removed and the cavity thus extended 
to the floor of the pulp chamber it is called the sub-pulpal 
wall. 

Illustration : Buccal and lingual cavities have — 

A mesial wall, 

An occlusal wall, 

A distal wall, 

A gingival wall, 
And— 

A fifth wall, called the axial wall. 
Rule: That wall of a cavity in an axial surface of a 
tooth that covers the pulp is called the axial wall. If the 
pulp of the tooth is removed the cavity is extended to 
include the pulp chamber and the wall takes the name of 
the wall of the pulp chamber. 

Simple mesial or distal cavities (proximate cavities), 
in the bicuspids and molars, have — 
A lingual wall, 
A buccal wall, 
A gingival wall, 
An occlusal wall, 



12 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

And— 

An axial wall. 
But as mesial and distal cavities are usually prepared they 
become mesio-occlusal (or disto-occlusal) cavities (com- 
plex cavities), the occlusal wall is missing and a step is cut 
in the occlusal surface. 

Rule: When one of the surrounding walls of a cavity 
is missing by reason of extension of decay, or by extension 
by cutting in the preparation for filling, so as to involve 
another surface, a complex cavity is formed and the remain- 
ing walls extend to the new surface involved. 

Therefore, when a mesial or a distal cavity in a bicuspid 
or molar has involved the occlusal surface, the buccal and 
the lingual walls will terminate at the occlusal enamel mar- 
gin. The axial wall will also extend to the occlusal enamel 
margin if no step has been formed, and the occlusal wall 
will be missing. When a step has been formed its walls 
will be named as in a simple occlusal cavity, except that 
that wall toward the cavity from which the step is formed 
will be missing. 

Therefore, mesio-occlusal (or disto-occlusal) cavities 
in the bicuspids and molars have in the proximate portion 
(mesial or distal) — 

A gingival wall, 

A buccal wall, 

A lingual wall, 
And— 

An axial wall.. 
In the step portion — 

A mesial (or distal) wall, 

A buccal wall, 

A lingual wall, 
And— 

A pulpal wall. 
Notice here that in mesial cavities the mesial wall of the 
step portion will be missing, and in distal cavities the 
distal wall of the step portion will be missing. 

In a mesio- or disto-occlusal cavity in a molar or bicuspid 
in which the pulp is removed, the pulpal and axial walls 
are removed. The floor of the pulp chamber becomes the 



NOMENCLATURE. 13 

sub-pulpal wall of the cavity. This is usually distinct from 
the gingival wall, because it is on a different level. There- 
fore, a mesio- or disto-occlusal cavity in a molar or bicuspid 
with pulp removed has — 

A buccal wall, 

A lingual wall, 

A gingival wall, 

A distal (or mesial) wall, 
And— 

• A sub-pulpal wall. 
Also some portions of the mesial (or distal) wall of the 
pulp chamber will remain next to the gingival wall as a 
mesial (or distal) wall. In a bicuspid or molar with a 
single broad pulp canal the pulp chamber has no floor, and 
of course there will be no sub-pulpal wall. 

Proximate cavities in the incisors and cuspids, on 
account of the wedge-like or triangular form of these sur- 
faces, have but three surrounding walls — 

A labial wall, 

A lingual wall, 

A gingival wall, 
And— 

An axial wall. 
When in incisor or cuspid proximate cavities the incisal 
angle becomes involved so that its removal is required, a 
complex cavity is formed by cutting an incisal step. There 
is in this case no change in the naming of the walls of the 
proximate portion of the cavity, as no one of the walls 
named has been completely removed. But the step por- 
tion will have — ■' 

A lingual wall, 

A labial wall, 

A mesial (or a distal) wall, 
And— 

A pulpal wall. 
Labial and lingual cavities in the incisors and cuspids 
have — 

A mesial wall, 

A distal wall, 

A gingival wall, 

An incisal wall, 



14 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

And— 

An axial wall. 

Angles of Cavities. 

In naming cavity walls and angles the typical idea of 
the cavity is that of a cuboid space or the form of a box. 
And no matter how irregular the actual form of the cavity r 
its walls and angles are named as if the form were regular. 

Each simple cavity has two sets of line angles, and one 
set of point angles. 

Rule : All line angles are formed by the junction of 
two walls along a line, and are named by combining the 
names of the walls joining to form the angle. Thev are, 
therefore, named in two terms. 

Rule: All point angles are formed by the junction of 
three walls at a point, and are named by joining the names 
of the walls forming the angle. They are. therefore, named 
in three terms. 

In simple cavities one set of line angles are formed by 
the junction of the four surrounding walls with each other, 
and form lines which run from the enamel margin to the 
floor or pulpal wall in occlusal cavities, or to the axial wall 
in axial cavities. A second set of line angles are formed 
by the junction of the surrounding walls with the floor, 
or pulpal wall in occlusal cavities, or with the axial wall 
in cavities in the axial surfaces of the teeth. These are 
called the pulpal line angles, and the axial line angles, 
respectively. 

The point angles are formed in those corners where the 
one set of line angles meet the other set at the corners of 
the cavity. The broader rule for naming angles to which 
there is but a single exception is : 

Rule: All angles of cavities are named by combining 
the names of the walls joining to form the angle. 

Illustrations: (Each angle named is formed by the 
junction of the walls, the names of which enter into the 
name of the angle.) 



NOMENCLATURE. 1 5 

Occlusal cavities have — 
A mesio-buccal angle "] 



A mesio-lingual angle 
A disto-buccal angle f 



ist set. }■ Line angles. 



J 

y 2(1 set J- Pulpal line angles. 



A distolingual angle 

A bucco-pulpal angle "] 
A linguo-pulpal angle 
A mesio-pulpal angle 
A disto-pulpal angle 

A mesio-bucco-pulpal angle ] 

A disto-bucco-pulpal angle I ^ . , 

. ,. ,,',(■ Point angles. 

A mesio-linguo-pulpal angle 

A disto-linguo-pulpal angle 

In case the pulp is removed the pulpal wall is removed, 
and the floor of the pulp chamber becomes the sub-pulpal 
wall of the cavity, and the pulpal angles become sub-pulpal 
angles. 

A buccal or a lingual cavity in molars or bicuspids has — 

A mesio-gingival angle ] 

A disto-gingival angle I , .. . 

. , , , l ist set of line angles. 

A mesio-occlusal angle 

A disto-occlusal angle J 

And— 

An axio-gingival angle ^) 

An axio-mesial angle 2d set of line angles, or 

An axio-occlusal angle j axial line angles. 

An axio-distal angle 

An axio-mesio-gingival angle "") 

An axio-mesio-occlusal angle 

An axio-disto-occlusal angle 

An axio-disto-gingival angle 

A simple mesial or distal cavity in a bicuspid or molar 

has — 

A linguo-gingival angle ^ 

A bucco-gingival angle . ,. , 

i ,. , , , y ist set of line angles. 

A lmguo-occlusal angle 

A bucco-occlusal angle 



j- Point angles. 



l6 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

An axio-lingual angle ^) 

An axio-occlusal angle 2d set of line angles or 

An axio-buccal angle axial line angles. 

An axio-gingival angle j 

An axio-linguo-gingival angle 1 

An axio-bucco-gingival anHe ,., . 
. . v , , * }- Point angles. 

An axio-lmguo-occlusal angle 

An axio-bucco-occlnsal angle 

But in mesial and distal cavities in the bicuspids and 
molars as prepared for filling, the occlusal wall is generally 
cut away and a step formed in the occlusal surface, form- 
ing a complex cavity. In this case the occlusal wall is 
missing and all of the angles formed by the junction of 
this wall with others are also missing. Then the step in 
the occlusal surface has its angles the same as in a simple 
occlusal cavity, except that the angles pertaining to the 
missing wall, mesial or distal, are also missing. This is a 
universal rule with complex cavities. 

Hence a mesio- or disto-occlusal cavity has in its mesial 
or distal portion — 

A bucco-gingival angle ) r ,. 

. ,. . . , , y ist set of line angles. 

A hnguo-gmgival angle j 

An axio-buccal angle } 

An axio-lingual angle > 2d set of line angles. 

An axio-gingival angle J 

An axio-bucco-gingival angle ),-»■. x -, 

. ,. . . , . >• Point angles. 

An axio-hnguo-gmgival angle j 

And in the step portion — 

A mesio- for disto-) buccal angle ) ist set of line 

A mesio- (or disto-) lingual angle j angles. 

A mesio (or disto-) pulpal angle \ , , .. 

v ' r r fe 2d set of line 

A linguo-pulpal angle V , 

x , , i i ( angles. 

A bucco-pulpal angle j 

A mesio- (or disto-) bucco-pulpal angle \ Point an- 

A mesio- (or disto-) linguo-pulpal angle I gles. 

And a pulpo-axial angle formed by the junction of the 

pulpal wall of the step with the axial wall of the mesial or 

distal cavity. 

The rule illustrated in the above is universal. A buccal 



NOMENCLATURE. IJ 

cavity united with an occlusal cavity would also have its 
pulpo-axial angle. • The angles belonging to the occlusal 
wall of the buccal cavity would be missing, and the angles 
belonging to the buccal wall of the occlusal cavity would 
also be missing. This, however, makes no difference what- 
ever with the naming of the remaining angles. If, how- 
ever, the pulp of the tooth is removed, removing the axial 
and pulpal walls, the angles with these walls are also 
removed and the angles of the pulp chamber (sub-pulpal 
angles) substituted. 

Labial or lingual cavities in the incisors and cuspids 
have — 

A mesio-gingival angle "^ 

A disto-gingival angle ' 

. .... ° I i st set of line angles. 

A mesio-mcisal angle & 

A disto-incisal angle 

An axio-gingival angle ^ 

An axio-mesial angle ' 

. . j. ^ , ■ , y 2d set of line angles. 

An axio-distal angle fe 

An axio-incisal angle 

An axio-mesio-gingival angle ^| 

An axio-disto-gingival angle 

An axio-mesio-incisal 

An axio-disto-incisal angle J 
Mesial and distal cavities in the incisors and cupids 
have, on account of their triangular form, but three angles 
instead of four. They have: 

A labio-gingival angle ] 

A linguo-gingival angle v ist set of line angles. 

*An incisal angle ) 

An axio-labial angle ] 

An axio-lingual angle V 2d set of line angles. 

An axio-gingival angle ) 

An axio-labio-gingival angle "J 

An axio-linguo-gingival angle > Point angles. 

An axio-incisal angle ) 

In mesial and distal cavities in the incisors and cuspids 

* Note. — The incisal angle given here is the one exception to the rule of naming 
cavity angles. If the rule were followed strictly it would be the labio-lingual angle, for 
it is formed by the junction of these two walls. However, the name, incisal angle, can- 
not be mistaken. 
3 



^ y Point angles, 
angle | & 



l8 THE TECHNICAL PROCEDURES IX FILLING TEETH. 

involving the loss of the incisal angle, or corner of the 
tooth, the incisal angle and the axio-incisal angle will be 
missing and the incisal step when formed will have its ~t: 
of angles. These are — 

A pulpo-distal (or mesial) angle ^| 
A pulpo-lingual angle J 1st set of line 

A pulpo-labial angle J angles. 

A pulpo-axial angle 

A mesio- (or disto-) labial angle | 2d set of line 
A mesio- (or disto-) lingual angle j angles. 
A mesio- (or disto-) labio-pulpal angle f Point an- 
A mesio- (or disto-) linguo-pulpal angle j gles. 
While all angles are theoretically and actually present 
as named, and according to the rules given and illustrated, 
these incisal steps are so narrow that it would rarely be 
desirable to name the point angles in any directions for 
cavity preparation or in cavity description. 

These lists of cavity angles may seem long and tedious, 
but it must be remembered that in any directions for the 
preparation of cavities, or in cavity descriptions, very few 
of them need to be mentioned. However, the student 
should be able to understand just what is meant when any 
one of them is mentioned, or be able to name any of them 
in any cavity. This he will not do by memorizing lists 
that are given, but by so learning the application of the 
rules as to be able to name at once any angle of any cavity. 

Nomenclature of Enamel Margins. 

The enamel margin includes the whole outline of the 
cavity and is equivalent to the marginal lines of the cavity. 
In this sense the enamel margin marks the outlines of the 
cavi: 

The cavo-surface angle f a cavity, or of the enamel, 
is the angle formed by the junction of the wall of the cavity 
with the surface of the tooth. The cavo-surface angle 
cavity will ordinarily be of enamel : under some unusual 
conditions it may be of dentin : or in buccal and labial cav- 
ities that extend beyond the gingival line the cavo-surface 
angle will be of cementum. The term cavo-surface angle 
sed especially when it is desired to indicate the form 



NOMENCLATURE. 19 

to be given this angle in any particular portion of the 
enamel margin, or outline of a cavity ; as, the buccal cavo- 
surface angle was beveled. 

The dento-enamel junction is the line of junction of the 
dentin and enamel as it appears in the walls of cavities. 

The enamel wall is that portion of the wall of a cavity 
which consists of enamel. It includes the thickness of the 
enamel from the dento-enamel junction to the cavo-surface 
angle. 

The dentin wall is that portion of the wall of a cavity 
which consists of dentin. 

The Planes of the Teeth and the Inclination of Cavity 

Walls. 

The teeth have three planes which may frequently be 
used to advantage in cavity description, and especially 
in speaking of the inclination of cavity walls. 

The horizontal plane is at right angles to the long 
axis of the tooth, and may be supposed to cut through the 
crown at any point in its length. 

The axio-mesio-distal plane, or the mesio-distal plane, 
passes through the tooth mesio-distally parallel with its 
long axis. 

The axio-bucco-lingual plane, or the bucco-lingual plane, 
passes through the tooth bucco-lingually parallel with its 
long axis. In the incisors and cuspids this is the labio- 
lingual plane. 

The inclination at which walls of cavities are cut, or of 
the dentin wall and the enamel wall, when each is spe- 
cifically mentioned, is reckoned from these planes of the 
teeth. When great accuracy of statement is desired the 
inclination may be given in centigrades. More generally 
the term outward inclination, or inclined outward, is used, 
with some word expressing degree, as slightly, strongly, 
etc. In this use of words the wall of the cavity men- 
tioned is always inclined away from the plane of the tooth 
in passing from within outward. The enamel wall and the 
dentin wall of any given part of a cavity may be on differ- 
ent inclinations ; for instance, the lingual dentin wall of 
a mesial cavity in a first molar tooth may be cut in the 
mesio-distal plane and the enamel wall inclined outward 



20 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

five or six centigrades. This will make a slight angle at the 
dento-enamel junction. 

The bevel of the cavo-surface angle is always reckoned 
from the plane of the enamel wall. 

The Use of Divisions of the Surfaces of the Teeth in 
Cavity Description. 

Whenever we wish to indicate in words the portion of 
a surface of a tooth involved in decay, or the extent of a 
cavity, we may conveniently do so by an imaginary 
division of the surface decayed into thirds, fourths or fifths. 
This division may be mesio-distally upon a buccal, lingual, 
or occlusal surface, or occluso-gingivally upon a buccal, 
lingual, mesial, or distal surface, or it may be bucco-lin- 
gually upon an occlusal, mesial, or distal surface. In other 
words, the divisions may be made upon any one of the 
planes of the tooth. 

For instance, of a cavity in a buccal surface we may 
say it involves the middle third mesio-distally and the 
gingival third occluso-gingivally. Or if the cavity is 
broader we may say it involves the middle three-fifths 
mesio-distally and the gingival half of the surface occluso- 
gingivally. 

In this use of words it must be borne in mind that 
when the adverbial form is used, it indicates direction. 
Mesio-distally means from mesial to the distal. Bucco- 
lingually means from the cheek toward the tongue, etc. 
This use of words is so simple that it should only require 
mention to be perfectly understood. Surgeons continually 
use this plan in speaking of the location of fractures of 
the bones. As, for instance, the humerus was broken at 
the junction of the middle and upper third, or the radius 
was broken in the middle of the lower third, etc. There 
is no need of any specific rules for this use of words in 
dividing the surfaces of the teeth in cavity descriptions, 
as any divisions intelligently made will be readily under- 
stood, and the portions of the surface involved quite 
accurately described. If it is said that a cavity in the 
mesial surface of a first lower molar extends from the 
occlusal surface to the junction of the gingival and middle 



CAVITY PREPARATION. 21 

third, and bucco-lingually from the mesio-buccal angle to 
the junction of the middle and lingual third, it should be 
understood. The same conception of the cavity should be 
obtained if it is said that it occupies the buccal two-thirds 
bucco-lingually, or that it occupies the buccal and middle 
third. There is scarcely any limit to the use that may be 
made in cavity descriptions of these divisions of the sur- 
faces of the teeth. 

Cavity Preparation. 

GENERAL PRINCIPLES. 

There are certain fundamental principles that are gen- 
eral to the excavation of carious cavities in the teeth, the 
observance of which will simplify and facilitate these 
operations. 

Order of Procedure. 

Obtain, first, the required outline form. 

Obtain, second, the required resistance form. 

Obtain, third, the required retention form. 

Obtain, fourth, the required convenience form. 

Fifth, remove any remaining decayed dentin. 

Sixth, correct the form of, and smooth the enamel wall, 
bevel the cavo-surface angle, and make the toilet of the 
cavity. 

The careful observance of this order of procedure by 
the student will greatly facilitate his operations, lead to 
more careful consideration of the requirements in indi- 
vidual cases, and will . guide him to the use of the 
appropriate instrument for the different parts of the 
operation. 

Outline Form is the form of the area of the tooth sur- 
face to be included within the outline, or enamel margins,, 
of the finished cavity ; the laying out of and cutting to' 
these lines should be the first thing considered and accom- 
plished. In all pit cavities the outline of the cavity will be 
found by cutting away all enamel overhanging the decayed 
area, completely uncovering it, and following out any 
sharp grooves connecting with the cavity to such points 
as will enable a perfect finish to be given to the margins 
of the filling when placed. This should always be done 
before there is any attempt made to remove the decay from 



22 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

the deeper parts of the cavity. As these cavities occur in 
surfaces of the teeth that are habitually clean., except for 
lodgments in the pits or fissures in which the decay begins, 
no further extension for prevention is required. In this 
class of cavities this work is done generally with chisels 
and the enamel hatchets. However, in the first opening of 
pits in which but little decay has occurred, and in follow- 
ing out fissures and grooves, the bur is often the best 
rument. In smooth-surface cavities, that is. in proxi- 
mate cavities, and buccal and lingual cavities, which do not 
begin in pits or fissures, but which occur in the central 
portion of an area of uncleanliness that is habitual, in which 
the superficial injury to the enamel tends to spread, the 
laying out of the outline form of cavities is done upon a 
different principle. In these it is not simply cutting away 
rrhanging enamel for the exposure of the dentin already 
decayed, but the object should be to include within the 
outline of the cavity such portions of the surface as are 
especially liable to decay in the future. As decay is liable 
to occur upon surfaces habitually unclean, and only upon 
the unclean areas, the whole of the habitually unclean area 
should be included within the outline of the cavity. This 
requires a careful study of the conditions surrounding each 
smooth-surface cavity and the extension of the cavity 
outlines to include the area of the surface that may have 
suffered superficial injury, or is in danger of decay in the 
future. This will often require that sound enamel and 
dentin be cut away to obtain the correct outline form, and 
is known as extension for the prevention of the recur- 
rence of the decay. The study of the case should be made, 
the outline determined upon, and the cavity cut to the 
outline form required as the first procedure. 

If the student will take a large number of decayed teeth 
and select all of those that have small cavities in some one 
or more of their surfaces that properly represent the place 
of the beginning of decay, he will find a remarkable uni- 
formity as to the particular spot in each individual sur- 
face in which decay begins. In all of the pit and fissure 
cavities he will find that the decay of the enamel, super- 
ficially, is confined to the immediate pit or fissure, but that 



CAVITY PREPARATION. 23 

it spreads in the internal parts of the tooth and the enamel 
finally is decayed from the inside outward. Backward 
decay of enamel. In all, or nearly all of the smooth- 
surface decays, when small, he will find a different con- 
dition, in which the decay beginning in the surface of 
the enamel tends to spread superficially on the surface from 
some point, usually central to the surface, toward the mar- 
gins of the surface. In this superficial spreading of decay 
the widest possible variations will be found, from decays 
of exceedingly small superficial area to those that are 
very broad. It is only after the decay has penetrated the 
dentin considerably that the enamel is undermined, as in 
the pit and fissure cavities. In this study the student 
should note particularly the number of decays he can find 
beginning upon the axial angles of the teeth and make a 
careful comparison of the number of these with those 
beginning centrally upon the surfaces. This will demon- 
strate very certainly that the axial angles of the teeth are, 
on account of their position, comparatively immune to 
decay, and point out to him the directions and extent to 
which extensions of cavities should be carried in their 
preparation for filling to prevent the recurrence of decay 
after the filling has been made. In this he will find that 
extensions should be made toward the angles, and that 
such extensions should never be carried past the angles. 
The central area is most liable to the beginning of decay, 
the angles least liable to decay. Hence, any extension 
beyond an axial angle would be an extension into a region 
of greater liability to decay. 

Resistance Form is that shape given to a cavity 
intended to afford such a seat for the filling as will best 
enable it to withstand the stress brought upon it in 
mastication. Its importance stands in direct relation to 
the degree of the exposure of the filling to the occlusion 
and to the strength of the closure of the teeth. It is neces- 
sary to provide for a force of from one to two hundred 
pounds, and in some cases more. The resistance form 
consists in a flat seat for the filling, cut at right angles 
with the direction of the stress of mastication, or usually 
at right angles with the long axis of the tooth. In occlusal 



24 THE TECHNICAL PROCEDUKZ- IN FILLING TEETH. 

ties, for example, the floor or pulpal wall is to be cut 
flat and all of the surrounding walls should be cut to 
definite angles with the pulpal wall. In proximo-occlusal 
cavities, in which the greatest possible support is needed, 
the gingival wall of the proximate portion is cut flat, and 
in the horizontal plane of the tooth, and extended from 
buccal to lingual into fairly definite corners or angles. 
The step is also given a flat horizontal seat. Generally this 
- easily attained by the same instruments and by the same 
modes of cutting used in gaining the outline form, if the 
two objects are held strictly in view. 

Retention Form is the provision for preventing the fill- 
ing from being displaced. A large part of this is pro- 
vided for by the resistance torm. But it is further required 
that provision be made that will prevent the filling from 
being thrown out of the cavity by such lateral or tipping 
force as may be Drought against it. All cavities should be 
provided with ample retention form, but this provision is 
required in its more perfect form in mesio- or disto- 
occlusal cavities in the bicuspids and molars. In these the 
provision is made in the form of a step cut into the occlusal 
surface, which is more or less dovetailed. In most cavities 
the retention form is made by so shaping certain of the 
opposing walls that they will be strictly parallel or slightly 
undercut in order that when the filling material is thor- 
oughly packed between them it will be securely held in 
place. This is done variously in different situations. It 
is to be looked to especially when the outline and resist- 
ance form of the cavity has been developed. Formerly 
pits and grooves were much depended upon for this pur- 
se, but have proved delusive, so that latterly it has been 
required that the form of the walls be such as to perform 
this function. 

Convenience Form, though secondary to other points in 
the formation of cavities, should not be neglected. When 
the general form of the cavity has been developed, modifi- 
cations are to be made that will render the form more 
convenient for packing the filling material. Often by cut- 
ting a wall away to a certain inclination the plugger point 
will reach some portion of the cavity better, or at a more 



CAVITY PREPARATION. 25 

available angle, enabling the operator to pack gold more 
certainly and more securely in certain important parts of 
the cavity. Also such cutting may render the filling so 
much more convenient as to save time and much wear and 
tear upon both patient and operator. 

A second order of convenience form is slight undercuts 
situated in angles or other parts of the cavity as starting 
points in packing gold, or that will hold the first portions 
of the filling material while other portions are being 
packed, or until the true retention form of the cavity has 
been filled. The study of the vise of these conveniences 
and the wise placing of them is especially important, as it 
assists in starting the filling and securing the first portions. 

These pits and grooves are .usually placed in the axio- 
linguo-gingival and axio-bucco-gingival angles of proxi- 
mate cavities, and in similar positions in other cavities. 

Removal of Remaining Carious Dentin. — Generally 
when the cavity has been cut to form, no carious dentin 
will remain. But in the larger decays it will often be a 
question whether or not the pulp will be exposed when all 
decayed dentin overlaying it is removed. It is especially 
an object that we do not cut toward the pulp until the 
cavity is otherwise well prepared, for the reason that if a 
pulp exposure is found the cavity shall be fully cleaned 
and ready for the immediate treatment of the pulp in any 
way indicated. Then when this stage in cavity prepara- 
tion has been reached, the remaining softened dentin is 
carefully and completely removed with broad spoon exca- 
vators, usually with the 20-9-12. It will often be required 
that the pulp of a tooth be exposed for the purpose of 
making an application to destroy it. In all of these cases 
the overhanging enamel should be removed and the walls 
of the cavity completely cleaned and so formed as to safely 
hold the temporary filling, before cutting toward the pulp. 
When all of this has been done and after the rubber dam 
is securely in place, lift off the remaining decay with spoon 
excavator 20-9-12, laying the pulp bare. If this is properly 
done very little pain is induced. 

Finishing the enamel wall and beveling the cavo-sur- 
face angle of the enamel is the last cutting done in the 



26 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

preparation of a cavity. This should always be done with 
the rubber dam in place and with all provisions made for 
the immediate placing of the filling material. 

The cavo-surface angle of the cavity in every part of 
its outline should receive especial attention. The plane of 
the enamel wall should be as nearly as practicable in the line 
of the length of the enamel rods, or such as will certainly 
cut more from the outer than the inner ends of the rods, 
and should be made smooth by a light planing motion of a 
sharp chisel or enamel hatchet, the motion being in line 
with the length of the margin. When this has been satis- 
factorily accomplished the cavo-surface angle of the enamel 
should be cut to a distinct bevel outward, also by a plan- 
ing motion of the chisel, enamel hatchet or the gingival 
margin trimmer, used very lightly. The depth of this 
bevel should generally not include more than one-fourth 
the thickness of the enamel wall. The angle of the bevel 
should be from six to ten centigrades from the plane of 
the enamel wall. The object is, first, to cut away any 
loose ends of enamel rods that might afterward fall away 
and render the margin imperfect ; and, secondly, to 
strengthen the cavo-surface angle of the enamel as a safe- 
guard against possible checking in packing the filling 
material. 

In this last work, two things should be held closely in 
view. The cavo-surface angle of the enamel is friable and 
readily broken by violence, and beveling will materially 
lessen this liability. But the marginal angle of the filling 
material which covers the bevel must not be made too thin 
by too great a bevel of the cavo-surface angle of the enamel. 
If so. it will have no strength and will tend to roughen 
and in this way render the margin imperfect. Therefore, 
the bevel of the cavo-surface angle of the enamel must not 
be too great. 

Finally, the toilet of the cavity is to be made. This 
consists in freeing all of its surfaces from the chips and 
dust that have accumulated during the excavation. The 
bulk of this is done, of course, with the chip blower during 
the progress of the excavating. But there will remain some 
fine dust upon the walls and margins that can not be 



INSTRUMENTS AND INSTRUMENTATION. 27 

removed in this way. It is not well to wash this with any 
known liquid, for even with the use of pure alcohol, and 
after drying with the air syringe, something will be left 
coating the walls which injures them for the purposes 
intended. The best thing yet devised is thorough wiping, 
or sweeping, of all parts of the cavity with absorbent 
cotton or with bits of punk held in the pliers. This should 
be well done and then the cavity is ready for filling. 

Rule : No moisture of any kind whatever should enter 
a cavity after the last of the cutting is done, and if by any 
accident a portion of the cavity should become wet, it 
should be dried thoroughly and then that portion that has 
been damp should be freshened by cutting away the 
surface. 

Instruments and Instrumentation. 

The cutting instruments required for preparing cavities 
have been adopted after long and careful study of the 
needs of students in school work. The set has been 
arranged especially with reference to teaching methods of 
preparing cavities, and for facilitating the actual work. 
It is such as will be best in learning to do these difficult 
operations, and it is to this end that they are adopted. 

Each of the names we apply to instruments has a 
definite meaning. They are descriptive of the uses, as 
excavator, plugger, separator, or the manner of use, as 
hand plugger. They describe the form of blades of cutting 
instruments, as hatchet, hoe, spoon, or they describe the 
form of the shank, as contra-angle, bin-angle, cow's-horn 
plugger. 

Note here especially that there are four classes of names. 
First, those which denote the purpose, which we call order 
names, as plugger, excavator; second, those which denote 
position or manner of use, sub-order names, as hand or 
mallet plugger, enamel hatchet ; third, those which describe 
the form of point, class names, as hatchet, spoon ; and 
fourth, those which describe the form of the shank, sub- 
class names, as bin-angle, contra-angle, cow's-horn or 
spiral. 

The names we apply to instruments are classified as 
follows : 



28 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

Order names, 
Sub-order names, 
Class names, 
Sub-class names. 
Order names denote purpose, and answer the question 
"what for?" 

Examples : Excavators, 
Pluggers, 
Separators, 
Scalers, 
Clamps, etc. 
Sub-order names denote the manner or position of use, 
and answer the question "where or how used?" and are 
usually a suffix to an order name. 
Examples : Hand mallet, 
Hand plugger, 
Mallet plugger, 
Enamel hatchet, 
Push scaler, 
Pull scaler, 
Molar clamp, etc. 
Glass names are descriptive of the working point of the 
instrument. 

Examples : Hatchet, 
Hoe, 
Spoon, 
Discoid, 
Cleoid, 

Serrated plugger, 
Smooth plugger, etc. 
These are also used as suffixes to order names, as in the 
last two ; and also as in hatchet excavator, hoe excavator, 
etc. 

Sub-class names describe the shape of the shank of the 
instrument. 

Examples : Mon-angle, 
Bin-angle, 
Triple-angle, 
Contra-angle, 
Cow-horn, 
P>avonet, etc. 



INSTRUMENTS AND INSTRUMENTATION. 20, 

These names are often combined for more complete 
descriptions of the instruments named, thus : Mon-angle 
excavator, or, mon-angle hatchet excavator, bin-angle 
spoon excavator, etc. In these combinations each name 
is descriptive of some part of the instrument, or of its 
uses.* 

In addition to these we have adopted formula names 
for the cutting instruments that describe each individual 
instrument so accurately that when learned each one will 
be known when its formula name is spoken. This is neces- 
sary in order that a teacher may be understood when 
speaking of the uses of particular instruments in lectures, 
or that students may understand the directions of demon- 
strators in the infirmary. 

These formula names are made upon the same principle 
as that used by the carpenter in naming his chisels or 
augers, as half-inch chisel, one-inch chisel, three-quarter- 
inch auger, etc. But for us to sufficiently describe the 
point of an excavator so that we will know the particular 
instrument at sight, it is necessary that we give three 
measurements. We give first the class name, as hatchet, 
hoe, spoon, etc., and then give the formula of the point, or 
w r orking part. This formula consists of the measurement, 
first, of the width of the blade in tenths of a millimeter; 
second, of the length of the blade in millimeters ; third, 
the angle of the blade with its shaft or handle, in centi- 
grades, or hundredths of the circle. Note particularly that 
the width and length make up the size of the blade. Also, 
in order that the individual instruments of the set may be 
easily learned and remembered we confine the set to a 
regular order of sizes and angles of blade that will give a 
sufficient variety of forms. 

The set of cutting instruments consists of two lists of 
formulae. One of these we call ordinaries, and the other 
specials. Aside from the regular formula lists we have four 
instruments that are not made upon these formula lines. 
These we call side instruments. 



* Only the nomenclature and the uses of instruments will be given here. The phi- 
losophy of instrument forms has been well presented in the freshman year. 



3° 



THE TECHNICAL PROCEDURES IN FILLING TEETH. 



Dental Instrument Gauge. 

This gauge for dental instruments is used especially in 
the measurement of excavators, pluggers and burs. It is in 
the metric system. It is used as follows : 

i. Measure the width of the blade in the slot numbered 
from o to 50, which gives the width in^tenths' of a milli- 
meter. This is the first figure of the formula. 

2. Measure the length of the 
blade in the gradations on the 
principal shaft, which gives the 
length of the blade in millime- 
ters. This is the second figure 
of the formula. 

3. Measure the angle of the 
blade with its shaft by laying 
the handle of the instrument on 
the main shaft of the gauge, paral- 
lel with the lines, and bringing 
the blade (turned toward the 
small numbers) parallel with one 
of the gradations of the circular 
head. This will give the angle 
of the blade with the shaft in 
centigrades or hundredths of the 
circle. This gives the third fig- 
ure of the formula. 

These formulae are stamped 
on the handles of the excavators. 
Plugger points may be meas- 
ured and designated in a similar 
manner. 

The diameter of burs may be 
obtained by measurement in the 
slot. 

The Ordinaries.* 
The set of ordinaries is made 
up of hoes and hatchets ; nine 
hatchets and nine hoes, or eight- 
een instruments. In these ther.e 
are three widths and lengths of 




*See notebook. 



INSTRUMENTS AND INSTRUMENTATION. 



31 



blade (three sizes) and three angles of blade, no more and 
no less. The measurements of these make up the formula. 

Formulae of the Ordinaries— Hatchets and Hoes. 





S 


izes. 






Angles. 


12 


wide 


5 


long. 


6 


centigrades angle 


8 


" 


3 


a 


6 




6 


a 


2 


" 


6 




12 


a 


5 


a 


12 




8 


a 


3 


a 


12 




6 


u 


2 


" 


12 




12 


a 


5 


(i 


2 3 




8 


u 


3 


" 


23 




6 


" 


2 


a 


23 




Or this form may 


be used: 








Sizes. 






Angles. 


12 


wide 


5 


long. 


6 


centigrades angle 


12 




< 


5 


u 


12 




12 




t 


5 


a 


23 




8 




1 


3 


(C 


6 




8 




1 


3 


" 


12 




8 




1 


3 


it 


23 




6 




1 


2 


a 


6 




6 




i 


2 


a 


12 




6 




' 


2 


(i 


23 





Note particularly that the sizes are the same in each 
of the three angles, and that there are but three sizes and 
but three angles, all told, of these ordinaries, and also 
that the formulae are the same for hatchets and hoes. There 
are nine hatchets and nine hoes in the set. Or there is a 
large size, a middle size and a small size in three angles. 
When these facts are in mind and they have been handled 
a few times, one should be able to name each instrument 
at sight. To assist in this the formula of each instrument 
is stamped on the handle, so that each of the three sizes 
in each of the three angles can easily be picked out and 
examined. In learning to read the points, or to name them 
bi sight, one should pick out by aid of the figures upon the 
handles the three sizes of each angle of the hatchets and 
lay them together ; then do the same with the hoes ; then 



32 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

change them and lay together each size of the three angles 
and compare them in this relation to each other. After 
doing this a few times one should be able to pick out any 
instrument without referring to the formula upon the 
handle. We call them hatchet 12-5-6, hatchet 8-3-12, hoe 
8-3-12, or hoe 8-3-23, etc. 

The set of ordinaries have been so called because they 
include the forms that have been most used t>y dentists in 
the past. Instruments similar to them, but less perfectly 
assorted, are found in every dentist's operating case. The 
smaller sizes of this set are used but little except in the 
preparation of cavities in the incisor teeth, and mostly in 
the final shaping of the walls and angles of these cavities 
after they have been opened by other instruments. 

The hoe 12-5-6 used as a chisel is the most useful in- 
strument in opening cavities in the incisors, especially for 
cutting away the labial enamel margins until the propei 
form has been reached. The hatchet 12-5-6 performs the 
same office for the gingival wall. Very often, in the more 
delicate of this cutting, the middle sizes, i. e., hoe 8-3-6 
and hatchet 8-3-6, will serve better, and in many cases it 
will be found more convenient to use the same sizes in 
the angle of 12 centigrades, or the hoe 12-5-12 and hatchet 
12-5-12, etc., or the sizes 8-3. The smallest size, or 6-2-6 
and 12, are used only in shaping the internal parts of cavi- 
ties in the incisors and cuspids, and especially in squaring 
out the axial line angles of these cavities so that they are 
sharp and definite. The angles of 23 are convenient for 
reaching certain points not easily reached with the angles 
6 and 12, but are used much less than the latter. 

The Specials. 

The set of specials are so called because each instrument 
i* designed for a special use. The formulae of this set are 
upon a different set of sizes, the plan of measurement being 
the same. In these are also three widths and lengths of 
bJade, three sizes and one angle of blade of 12 centigrades 
for all except the binangled chisels, which are 6 centigrades 
an^le. 



INSTRUMENTS AND INSTRUMENTATION. 33 

Formulae of the Specials. 

Straight chisel, 20, width only given. 
Straight chisel, 15. 
Straight chisel, 10. 
Binangle chisel, 20-9-6. 
Binangle chisel, 15-8-6. 
Binangle chisel, 10-6-6. 
Enamel hatchets, rights and lefts, 20-9-12. 
Enamel hatchets, rights and lefts, 1 5-8-12. 
Enamel hatchets, rights and lefts, 10-6-12. 
Spoons, rights and lefts, 20-9-12. 
Spoons, rights and lefts, 1 5-8-12. 
Spoons, rights and lefts, 10-6-12. 

Gingival margin trimmers, rights and lefts, 20 (95)- 
9-12.* 

Gingival margin trimmers, rights and lefts, 20 (80) -9- 12. 
Gingival margin trimmers, rights and lefts, 15 (95)-9-i2. 
Gingival margin trimmers, rights and lefts, 15 (95)~9-i2. 

Formulas of Side Instruments. 

Hatchets, 5-3-28 and 3-2-28. 

Discoid, 20, and cleoid, 20. 

Of the three last groups of specials, the enamel hatchets 
are rights and lefts, because of the form of the bevel of the 
cutting edge. The spoons and gingival margin trimmers 
are made rights and lefts by the curve of the blade. All 
the specials are designed for special work. They are used, 
except the smallest size of the spoons, almost exclusively 
in the bicuspids and molars, and in these they should be 
used for almost all of the work of excavating. 

The chisels and enamel hatchets are used for chipping 
away the enamel in opening cavities in the bicuspids and 
molars, and in cutting the outlines to the required form. 
The enamel hatchets are used especially for cutting away 
the buccal, lingual and gingival walls of proximate cavities 
in these teeth and in shaping them. Also, both the chisels 

* Note — When it becomes necessary to designate the angle of the cutting edge of 
an instrument with its shaft, it is done by sliding it, without rotation, to the left, still 
keeping it parallel with the longitudinal lines, until the angle of the cutting edge corre- 
sponds with one of the lines of the larger numbers to the left. This number is then 
entered in brackets following the width number. When not so designated the cutting 
edge is at right angles with the length of the blade. 
3 



34 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

and enamel hatchets are used in the final shaping of the 
enamel wall and in beveling the cavo-surface angle of the 
enamel. 

The gingival margin trimmers are used for only the 
one purpose of beveling the cavo-surface angle of the 
enamel along the gingival wall of proximate cavities in the 
bicuspids and molars. For this purpose one pair has the 
edge cut at an angle of 80 centigrades with the shaft, which 
is right for beveling the gingival cavo-surface angle of the 
enamel in mesial cavities, and the other pair has the edge 
cut at an angle of 95 centigrades with the shaft, which fits 
them for beveling the gingival cavo-surface angle of the 
enamel in distal cavities. 

The spoons are used for scooping out softened material 
1 carious dentin) from the deeper parts of carious cavities. 
They should be used only after the walls have been cut to 
form by other instruments. They are not at all suited to 
cutting hard dentin. 

Side Instruments. — There are four side instruments in 
the set. They are called side instruments because their 
formulae do not coincide with those of either of the other 
sets. Of these the discoid (disc like) performs a service 
similar to the spoons, i. e.. the removal of softened dentin 
from the deeper parts of the cavity after the walls have 
been cut to form by other instruments. In positions in 
which the access is direct it is a more convenient instru- 
ment than the spoons, though generally the spoons are 
better. 

The cleoid is used most for trimming out the angles oi 
pulp chambers in order to reach the canals with the broach 
more readily, especially the canals in the mesio-buccal 
roots of the upper molars and the mesio-buccal and mesio- 
lingual angles in- the lower molars. 

The two hatchets. 5-3-28 and 3-2-2S. are used only for 
the purpose of undercutting the incisal angle of proximate 
cavities in the incisors and cuspids for the purpose of ob- 
taining retention form. They are designed for this special 
purpose and are used for nothing 1 else whatever. 



INSTRUMENTS AND INSTRUMEN'I AT10N. 35 

Instrument Grasps and Rests. 

The manner of holding instruments in performing dental 
operations is very important. There are two principal 
grasps : The pen grasp and the thumb and palm grasp, 
with modifications of both. 

The pen grasp is used for most operations. As implied 
in the term, the instrument is held in the fingers in the 
position, or with the same grasp, with which we would 
hold a pen, and the manipulation is carried on with the 
instrument held in that position, whether in cutting with 
an excavator or packing gold with a plugger. Perhaps 
nine-tenths of these operations should be done with the 
instruments held in that way. Occasionally positions are 
found in which the operation may be much facilitated by 
a modification of this grasp, made by bending the fingers 
into, or nearly into, the palm of the hand, thus inverting 
the position of the instrument so that it points directly at 
right angles to the length of the arm. This is called the 
inverted pen grasp. 

In the use of these grasps certain rests for the fingers 
should be sought and practiced until they are correctly ob- 
tained without especial thought. By the use of these rests 
operations can be much more accurately performed than 
without them, and they greatly limit the danger of injury 
to the patient by slips of the instrument. 

The rests are generally made by placing the third or 
fourth finger, preferably the third, upon the teeth of the 
same jaw in which the tooth operated upon is situated. In 
operating upon the molars the rest will be upon the anterior 
teeth. When operating upon the anterior teeth the rest 
will be found on either side of the tooth operated upon. 
Any effort to use the teeth in the opposite jaw for a rest 
will be found very unsatisfactory, on account of the move- 
ments of the lower jaw changing the relation of the rest 
and the tooth operated upon. Rests upon the soft tissues 
should be avoided as much as. possible, because they are 
unreliable at best, and always unsteady. 

In the thumb and palm grasp the shaft of the instrument 
is held in the palm of the hand in such manner as to oppose 
the working point to the thumb, and the thumb of the same 



36 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

hand is placed either upon the tooth upon which the opera- 
tion is performed or upon an adjacent one, to steady the 
instrument and to oppose a counter pressure. This grasp 
is not often useful, except when unusual force is to be 
applied. Neither can it be used successfully in very many 
positions. However, there are certain operations in which 
its use is very desirable, and each student should learn 
these by careful practice. It is especially useful with the 
Case cleaver in removing the enamel from the teeth for 
fitting bands for crowns, and may be used upon any of 
the upper anterior teeth, and often upon the first and 
second molars. 

The thumb and palm grasp may be used very success- 
fully with the chisel in opening cavities in any of the 
upper anterior teeth, and as far back as the first molars, 
though only in a limited number of positions. The re- 
quirement is that when the chisel is grasped in the palm 
of the hand and the thumb of the same hand applied to 
the tooth operated upon, or the one next to it, the instru- 
ment will come into position to be used effectively. When 
these positions are found the chisel can be used much more 
effectively than is possible with the pen grasp. It is there- 
fore desirable that this grasp be practiced at every oppor- 
tunity, and its use extended as much as possible. 

Sharpening Instruments. 

Nothing in dental practice is more important than the 
care of the cutting edges of instruments. No man ever 
yet became a good and effective dentist until after he had 
learned to keep his cutting instruments sharp. It is simply 
impossible to effectively prepare cavities for filling without 
sharp instruments. The dental student who can not, or 
will not, learn to keep the edges of his cutting instruments 
in good condition had better quit and go home, for he will 
not succeed as a dentist. A good stone is a necessity. 
1\ is of first importance that the stone be very hard. Our 
instruments are small, and if we attempt to use a soft 
stone the point will catch and ruin both the edge of the 
instrument and the surface of the stone. The stone should 
never be smaller than \y 2 by 5 inches. A stone somewhat 



INSTRUMENTS AND INSTRUMENTATION. 37 

larger is much better, but a smaller stone is a nuisance. 
A hard Arkansas stone is best. The hardness should be 
especially looked to in selecting a stone. The care of the 
stone is very important. It should be thoroughly oil- 
soaked and then wiped off. It may then be used dry or 
with oil, but however used it should be wiped off clean with 
oil upon a cloth after using. If this be not done the stone 
will soon fill up with the steel cuttings and it will fail to 
cut when the effort is made to grind with it. These steel 
cuttings are removed from the stone by the oil and the 
cloth. If the face of the stone becomes marred or unlevel 
from use, it may be refaced by rubbing it on a sheet of 
emery paper laid flat upon a smooth, level table or board. 
The facing should be finished on the finest grade of emery 
paper. A good stone should last a lifetime if well taken 
care of. 

The cutting edges of the excavators should be ground 
carefully, observing that the correct bevel of the edge be 
maintained and that the edge is kept straight. To this end 
instruments should be carefully applied to the stone and 
the correct position maintained throughout the back and 
forth motions of grinding. 

The spoons and discoids are ground by placing them 
on the stone so that the motion in grinding will be parallel 
with the length of the cutting edge, and during each stroke 
the instrument is rotated upon its edge in such a way that 
every part of the semi-circular edge will come against the 
stone in some part of each motion. This is easily done 
after a little practice. 

Care as to heating the instrument points while grinding 
is very important. If heavy pressure is made and the 
instrument moved rapidly upon the stone, enough heat 
will be quickly developed to draw the temper of the steel 
and ruin the instrument. It is well for the beginner to 
place one finger upon the point of the instrument while 
grinding, that he may feel the heat develop, until he has 
learned to judge accurately of this danger. 



38 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

Use of the Dental Engine. 

The dental engine has in recent years become an im- 
portant instrument in operative dentistry. It is used for 
certain parts of the work of excavating cavities, for trim- 
ming fillings to form after they have been inserted, and a 
large amount of the work of polishing is best done with it. 
For these several purposes engines should be equipped 
with certain sizes and forms of excavating burs, a few 
sizes and forms of finishing burs, stones for grinding and 
sandpaper disks of different grades of fineness, rubber disks 
for carrying polishing powders, etc. 

In excavating, the bur is nowadays indispensable, and 
yet but a small part of the excavating should be done with 
burs. The tendency among students is to continually use 
the bur too much and to use it in improper places. 

The forms of bur most useful are what are known as 
the inverted cone bur and the fissure bur. Round burs are 
not often used to advantage, and yet there are certain 
definite purposes requiring round burs. 

The sizes of burs are very important. With the dental 
engines with which we are supplied no large burs can be 
used to advantage, for the reason that the motion is con- 
veyed by a cable, which allows large burs to jump and 
chatter. Cord engines give to the bur a much smoother 
motion and better cutting power, but are not regarded as 
so convenient. Practically none of them have sufficient 
power to run a large bur to advantage. For our use, then, 
burs for excavating that are over one and one-half milli- 
meters in diameter should not be used at all. The most 
useful burs are one millimeter and less in diameter. The 
round bur is used only for the one purpose of opening pit 
cavities in which decay has only just begun. For this pur- 
pose round burs, from a little less than one millimeter to 
one and a half millimeters in diameter, should be used by 
placing them in the pit while in motion and swaying the 
hand-piece to and fro so as to rotate the bur laterally while 
it is rapidly turning upon its axis. This lateral motion of 
the hand-piece will cause the bur to cut much more rapidly 
than when held simply against the work. Use the smaller 
size first, and when it has entered the pit change it for a 



USE OF THE DENTAL ENGINE. 39 

larger, using this in a similar way, and follow this again 
with a larger size. Then the round bur should be laid 
aside and the cavity finished, if further enlargement is re- 
quired, with other instruments. There is no other use for 
a round bur in excavating cavities. It should never be 
used for removing decayed dentin. If the pit cavity 
requires no further extension the round bur should be fol- 
lowed by an inverted cone that will square out the pulpal 
or axial wall of the cavity and, make the angles with the 
surrounding walls sharp and definite. A cavity with 
rounded angles is the most difficult of all cavity forms to 
fill perfectly. For other purposes in excavating it is a 
matter of choice in individual cases between the use of the 
inverted cone and the fissure bur. These burs should be 
used in several positions, which will be pointed out. 

Cutting seats or steps for anchorage in mesio- or disto- 
occlusal cavities in the bicuspids and molars. — After the 
mesial or distal cavity has been well opened with cutting 
instruments, and the cutting of a step in the occlusal sur- 
face is required, choose a small inverted cone or fissure 
bur, never more than one millimeter in diameter, and begin 
within the dentin close against the dento-enamel junction, 
causing the bur to enter, and then draw it to the surface 
of the enamel ; engage it again in the same way and repeat 
the motion. With this movement, using a small bur, a 
groove is readily cut through the enamel into the center 
of the occlusal surface. In this cutting the line of the 
mesial (or distal) groove should be followed, because this 
is the weakest part of the enamel. If the bur is too large, 
it will not cut so well. It is only by concentrating the 
force on a small bur that the enamel can be cut to any 
advantage, and even then the cut should be made from 
within outward. After this first cut has been made the 
groove or channel formed should be broadened by chip- 
ping away the enamel with chisels, or the enamel hatchets, 
and the inverted cone bur again used to undermine the 
enamel upon either side, which is again chipped away. In 
this way a seat or occlusal step of any required extent is 
readily formed, the pulpal wall of which will have sharp 
and definite angles with its surrounding walls. 



40 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

Grooves that need to be cut out, merely for the pur- 
pose of finding a position for finishing the filling, i. e., when 
there is solid dentin beneath, are to be cut in the same 
manner, with the inverted cone or fissure bur. In none of 
these cases should any attempt be made to cut the enamel 
from without inward with the bur. Cutting enamel with 
the bur dulls the blades very quickly. After the bur has 
been used for this purpose a few times, it should be dis- 
carded and a new One employed. The dull bur may be 
sharpened by the instrument maker. 

In squaring out angles of cavities, the inverted cone but 
may often be used to advantage in such positions as are 
readily accessible, as in occlusal, labial and buccal cavities. 
Usually this is done by flattening the pulpal wall in oc- 
clusal cavities, or the axial wall in buccal or labial cavities. 
In order to accomplish this with the bur the approach 
must be such that the square end of the bur may be placed 
in the plane of the pulpal or axial wall to be formed, or, in 
other words, the axis of the hand-piece must be at right 
angles to the pulpal or axial wall to be formed. Then the 
side or periphery of the bur is engaged in the deeper part 
ot the rounded pulpal or axial wall, and made to cut toward 
one of the surrounding walls. This is then repeated in 
another direction, and the bur is finally carried in a similar 
way around the whole circumference of the cavity in such 
a way that its square end leaves the pulpal or axial wall 
flat, and its line angles with the surrounding walls are 
made sharp and definite. 

The contra-angle hand-piece is often useful for doing 
this work in occlusal cavities in the lower second and third 
molars, and occasionally in buccal cavities in these teeth. 
With it the proper position of the bur may be obtained in 
those places that are not accessible to the straight hand- 
piece. The right-angle hand-piece has been used much 
in the past for this purpose, but it is a very awkward 
instrument, for the reason that the working end of the bur 
i<- far out of the line of the axis of the hand-piece. This 
renders it ineffective. The contra-angle hand-piece reme- 
dies this defect. However, this instrument has not the 
same power and is never so effective as the straight hand- 



USE OF THE DENTAL ENGINE, 41 

piece, and should not be used in any case in which the 
straight instrument can be brought into position to do 
the work. In most cases this squaring out of the pulpal 
or axial walls to definite angles with the surrounding walls 
is done just as easily and quickly with the hoes 12-5-6, 
12-5-12, or the 8-3-6 or 12, used with a scraping motion. 
These instruments will reach any of these positions if the 
surrounding walls have been properly formed previous to 
their use. 

In making extensions for prevention in any of the axial 
surface cavities the small inverted cone burs may be used 
to advantage. If, in excavating proximate cavities, we find 
that after cutting the gingival wall to sound dentin it is 
desirable to extend the cavity further to the gingival, place 
the end of an inverted cone bur, five to eight-tenths of a 
millimeter in diameter, against the gingival wall upon the 
dentin, close against the dento-enamel junction, and incline 
the hand-piece just enough to cause the periphery of the 
bur to cut, and press it toward and into the bucco-gingival 
angle, then incline the hand-piece in the opposite direction 
and press the bur in the linguo-gingival angle. Now, by 
repetitions of these movements, cut as deeply to the gingi- 
val as may be required, keeping close against the dento- 
enamel junction. This undermines the enamel, which is 
now easily removed with the enamel hatchets. In extend- 
ing to the buccal or to the lingual the enamel hatchets 
generally serve best, but occasionally the operation is 
facilitated by starting a small inverted cone bur in the axio- 
bucco-gingival angle and drawing it to the occlusal, cutting 
away the dentin of the buccal wall just beneath the enamel, 
which is then removed with the enamel hatchet. The same 
operation is repeated upon the lingual wall. 

In this extension it is important that the bur be kept 
close against the enamel, so that it shall not cut into the 
tooth so deeply as to endanger the pulp. There should 
be no attempt to cut the enamel with the bur, for the 
reason, first, that it is not easily done, and, second, because 
it ruins the bur. Whenever it is regarded as important 
that enamel should be cut with a bur one must expect 
that the bur will be ruined in the operation. That is to 



42 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

say, the blades will be so dulled that it will be unfit for 
further use, and a new bur must be provided for the next 
operation. A good bur will cut dentin, however, for many 
operations. 

In making starting points for packing gold the smaller 
inverted cone bur is especially useful. In mesial and distal 
cavities in nearly all positions, starting points in the axio- 
Imguo-gingival angle and the axio-gingivo-buccal (or 
labial) angle are important conveniences. They are best 
made by placing the end of an inverted cone bur in the 
angles named, and by a slight swaying of the hand-piece 
cause the bur to enter just a little, then draw the bur to- 
ward the occlusal (or incisal if in incisor cavities), a short 
distance, making a slight groove leading away from the 
pit first formed to give strength to the gold when placed. 
The pit itself should not be directed into the gingival wall, 
or only slightly, but to the lingual or buccal (labial in the in- 
cisors and cuspids), and the groove should be close against 
the axio-buccal or axio-lingual line angle. In this method 
of cutting these starting points the square end of the bur 
gives a square floor to the pit at the point where the first 
piece of gold is placed, which prevents any tendency of 
the gold to roll from side to side in the first efforts to 
condense it, so that a very shallow pit, a mere corner or 
sharp angle, so to speak, is all that is necessary. It should 
be remembered always that these convenience points are 
not anchorage points for the filling, but are simply starting 
points for the temporary anchorage of the first pieces of 
gold. 

The use of drills should be confined to certain especial 
purposes. These should be used when for any reason it 
becomes necessary to cut into the pulp-chamber of a sound 
tooth, or one that has already been filled. This necessity 
occurs frequently because of hypersemia of, or death of, 
the pulp after a filling has been made, or from death of 
the pulp from a blow or some unknown cause. In these 
cases it is often necessary to cut from the surface of the 
tooth to the pulp-chamber, either through a filling or 
through the enamel and dentin. The bur is not suitable 
for this work. The flat drill, bi-beveled to a point, is the 



THE USE OF WATER. 43 

proper instrument, or the drill, followed by a round bur 
to enlarge the opening. In doing this where considerable 
tissue is to be cut through, it is best to use a small drill 
first, and when this has penetrated some distance, enlarge 
the opening with a larger drill or a round bur, then pene- 
trate further with the small drill and again enlarge. Pro- 
ceed in this way until the pulp-charnber is reached. In 
the attempt to drill deeply with a small flat drill the instru- 
ment does not clear itself of chips readily and is apt to 
heat; also, it is likely to be broken by any movement of the 
patient. 

The drill is also the best instrument for enlarging root- 
canals for setting posts or pins for artificial crowns. It 
will be seen that these uses of the drill are aside from 
cavity excavation. 

The Use of Water 

The use made of water in operative dentistry is very 
important. Every dental office should have a liberal supply 
of both warm and cold water. The use of water for the 
hands of the operator is in itself important, and the wash 
basin, while not necessarily before or about the operating 
chair, should be convenient, and in such position that the 
patient may at least know when the operator washes his 
hands. Cleanliness and neatness are important in gaining 
and in holding a practice. 

Water should be constantly ready for use at the operat- 
ing chair for washing the teeth and gums of patients. For 
use in the mouth, water should generally be heated to about 
105 degrees Fahrenheit, or just a little warmer than blood 
temperature. In the large majority of cases this tem- 
perature will be found most grateful to patients. If, how- 
ever, cases occur, as they will, in which some of the teeth 
are very sensitive to thermal changes, the temperature of 
105 degrees will cause considerable pain, and in such cases 
the temperature should be carefully reduced to gSy 2 de- 
grees, or blood temperature. 

The uses of water at the operating chair are : 

For cleaning the teeth preparatory to operating. 

For keeping the teeth and mouth free from blood and 



44 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

debris while removing calculus, or in doing any operations 
upon diseased gums, or while treating diseases of the peri- 
dental membranes. 

For washing cavities during any portion of the work of 
excavating that may be done before placing the rubber dam. 

For cleaning the necks of the teeth before applying the 
rubber dam. 

For treating the gums after removing the rubber dam. 

For removing debris and polishing powders during ap- 
portion of the polishing of fillings that may be done with- 
out the rubber dam. 

For any and all of these uses a good rubber-bulb water 
syringe, which will hold a little more than a gill, is neces- 
sary. A little bit of a water syringe is a nuisance. A 
syringe should be used with which the mouth can be 
flooded with water, or a strong, continuous stream thrown 
for several seconds. 

For cleaning the teeth preparatory to operating, warm 
water should be used in almost every case, even though 
the teeth are apparently in a cleanly condition. In the 
best of conditions there is usually more or less gummy ma- 
terial, containing many micro-organisms, about the necks 
of the teeth, or about cavities, especially proximal, buccal 
and labial cavities, which should be loosened up with scal- 
ers and removed with a strong stream of water. In very 
many cases the teeth should be cleaned with a rubber disk 
and powdered stone and washed clean with a jet of water 
before anything is done toward excavating cavities. In all 
cases the field of operation should be made clean as the 
first procedure. 

The use of water while removing calculus is impera- 
tive. The field of operation requires to be repeatedly 
washed with strong jets of water, in order to do both 
operator and patient justice. This is necessary in order 
to remove blood and debris that the next step of the opera- 
tion may be seen. It is necessary to impart a sense of 
cleanliness and comfort to the patient. It is necessary 
to the removal of particles of loosened calculus from about 
the necks of teeth. 

IrT^xcavating cavities water should be used freely in 



THE USE OF WATER. 45 

any portion of the operation that is done before placing 
the rubber dam. In many cases it is desirable to open 
cavities and do the rougher parts of the excavating before 
the dam is applied. During such part of the operation as 
may be done without the rubber dam the cavity should be 
frequently washed with strong jets of water of the proper 
temperature for the purpose of removing all debris from 
the cavity and from the mouth of the patient. 

Before placing the rubber dam, water should be used 
to free the necks of the teeth from micro-organisms, even 
in the most cleanly mouths. A thin scaler should be passed 
around all of the surfaces, loosening up any gummy sub- 
stance adhering to them, and this should be washed away 
with a strong jet of warm water. If the case is not espe- 
cially cleanly there is greater necessity for this proceeding, 
provided, of course, that this has not been done preparatory 
to some previous operation at the same sitting. 

The object of this care is especially to prevent pushing 
a mass of micro-organisms and debris under the free mar- 
gin of the gum by the rubber and the ligature. Often the 
gums are more or less bruised by this procedure, and if at 
the same time a mass of debris containing many active 
micro-organisms is crowded into the soft tissue and held 
there for a considerable time, the micro-organisms will 
take hold of this injured tissue, and cause very inconvenient 
soreness, or actual suppuration. Many incurable cases of 
phagedenic pericementitis are started in this way. 

After removing the rubber dam the gums should be 
treated with a thorough douching with warm water while 
kneading them thoroughly with ^he fingers of the other 
hand. This is especially important to the comfort of the 
patient. The rubber dam has been in place for a consid- 
erable time, perhaps for one, two or three hours, and dur- 
ing this time the free margins of the gums have been 
tightly compressed by the rubber and the ligatures or 
other appliances for securing it in place. The circulation 
of the blood through this part has been stopped. The 
douching, together with the kneading, causes the blood to 
return to these tissues, starts it into active circulation 
again, and removes any poisonous material that may have 



46 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

been forced into the gingival space by the rubber. It im- 
parts a feeling of comfort to the parts and causes at once 
the most complete feeling of rest from the operation that 
it is possible for the operator to give. 

The washing away of powdered stone and debris during 
and after polishing fillings should be thorough and com- 
plete, and the patient dismissed with a clean mouth, free 
from all grit and dirt of any sort that has been used. Al- 
ways look particularly to the comfort of your patients and 
they will reward you for your care. 

The Rubber Dam. 

The objects to be attained by the use of the rubber 
dam are : to keep cavities dry and clean while excavating 
and while making fillings; to better expose and bring the 
parts into view ; and to prevent ingress of saliva and micro- 
organisms during the treatment and filling of root canals. 

In using the rubber dam it should be remembered that 
it is disagreeable, sometimes painfully so, to patients, and, 
therefore, its use should be restricted to the actual neces- 
sities of the case in hand, and the time it remains in place 
should be made as short as practicable. 

When the cavity to be prepared is in sufficiently plain 
view, and the conditions are such that the saliva will not 
obscure the seat of operation, the rubber dam should not 
be placed until the rougher parts of the excavating is done. 
In excavating cavities in the upper teeth a considerable 
portion of the work may often be done before applying 
the rubber dam, but it should always be in place before the 
excavation is finished, and remain until after the filling is 
completed. The rule should be that the walls of a cavity 
should never become damp after the last of the cutting 
is done in their preparation. 

If, however, it appears from the position of the tooth, 
and the conditions present, that the field of operation will 
be continually overflowed by saliva, or that the case is 
particularly difficult to see, the rubber dam should be 
placed before beginning the operation. In proximate cavi- 
ties it is generally best to open the cavity by cutting away 
the overhanging enamel, and to determine the position of 



THE RUBBER DAM. 47 

the gingival wall of the prepared cavity with some degree 
of certainty before applying the rubber dam. This will 
usually facilitate the application of it, and in obtaining its 
proper position in relation to the gingival wall. 

Preparation* for Applying the Rubber Dam. 

The rubber dam should be tough and very elastic. 
Generally a medium thickness should be employed. It 
should be cut in pieces about six inches square. Before 
making any effort to apply it, the teeth should be well 
cleaned and douched with a stream of warm water from 
the syringe to free them from gummy material, and from 
collections of micro-organisms that would otherwise be 
forced under the free margins of the gums, or even into 
the soft tissues, by the ligatures or clamps. The inter- 
proximate space should be cleaned by use of the ligature 
passed between the contact points. In doing this the diffi- 
culties to be met with in passing the rubber between the 
teeth will be determined. The position and size of the holes 
in the dam should next be determined, together with the 
number of teeth to be included. Not less than three, gener- 
ally four or five, teeth should be included. If a front tooth is 
to be filled, include four or more, always one or two on either 
side of the tooth to be operated upon ; if a bicuspid or first 
molar, include one tooth to the distal, and at least two to 
the mesial; if the second molar and the cavity involves the 
distal surface, include the third molar; if the cavity does 
not involve the distal surface, the inconvenience of placing 
the rubber upon the third molar will be greater in many 
cases than to do the operation with, a clamp on the second 
molar. In all cases there should be as clear a field and as 
much room for operating as practicable. 

The holes in the rubber should be placed in such posi- 
tion that when applied it will cover the upper lip, lower 
lip and chin, but should not cover the nostrils of the patient 
and interfere with the breathing. The distance between 
the holes is an important consideration. They should al- 
ways be as far apart as the mesio-distal breadth -of the teeth 
to be included. In case of bicuspids and lower incisors 
that have thin necks mesio-distally, the distance should be 



48 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

a little greater. This is necessary to prevent the septum of 
rubber between the teeth from stretching into so narrow 
a band that it will fail to hug so closely to the necks of the 
teeth as to exclude moisture. 

Rubber Dam Grasps. 

The particular manner of grasping the rubber dam 
when about to apply it is very important., and should be 
studied with much care in the beginning of the student's 
experience. Certain ways of grasping the rubber dam are 
particularly suited to the application of it in certain posi- 
tions in the mouth, or to certain teeth ; also to certain posi- 
tions of the operator when applying it. If these are well 
learned in the beginning it will save much time, and much 
of the difficulty in attaining facility in this work. 

In considering these grasps the side of the rubber 
which, when applied, will be next the gingivae is called the 
gingival side, and that which will be toward the occlusal 
surfaces of the teeth is called the occlusal side. 

The first grasp is used when the dam is to be applied to 
the upper front teeth. Grasp the rubber between the 
thumb and finger of each hand, with the ends of the thumbs 
on the occlusal side of the rubber and their ends touching 
together immediately over the hole to be first used, and 
the finger-ends midway the balls of the thumbs. Stretch 
the rubber a little with the thumbs still touching end to 
end. Then stretch the rubber a little more, and, standing 
to the right and in front of the patient, pass the hole over 
the tooth, the right thumb on the lingual and the left on 
the labial side. In doing this, first place the free edge of 
the rubber at one side of the hole between the teeth, and 
with a slight sawing motion force it past the contact on 
that side. Then stretch it over the tooth and force it past 
the contact on its other side in a similar way. Xow carry 
each of the thumbs against the gingivae. At this point 
hold the thumbs in position for an instant, release the 
hold of the rubber with the fingers and allow it to draw 
around the neck of the tooth before loosing the pressure of 
the thumbs. Generally the rubber will be felt to draw 
around the thumbs/and then they should be given a slight 



THE RUBBER DAM. 49 

shaking motion, which will allow the rubber to draw 
around the tooth, before releasing the pressure, and remov- 
ing them. When the rubber is applied in this way it will 
generally be found to cling to the neck of the tooth and 
have its cut edge turned under the gingivae. Repeat this 
motion with each hole in the rubber, grasping it anew, and 
in the same manner for each, and pass it over the appro- 
priate tooth with a similar motion. This grasp and these 
motions will answer for all of the upper teeth as far back 
as the first molars. When applying it with this grasp to 
the teeth of the left side, the face of the patient should be 
turned strongly to the right ; or the operator should pass 
to the left side of the patient. 

The second grasp is a modification of the first, which 
allows the left hand of the operator to be passed around 
the head of the patient when standing to the right of, and 
partially behind, the chair. This will generally be found 
more convenient for the. upper teeth of the left side as far 
as the bicuspids. In this the rubber is grasped with the 
right hand in the same way as before, but with the left 
hand the grasp is inverted so that the forefinger takes the 
place of the thumb, or is on the occlusal side of the rubber, 
with the thumb about opposite the first joint of the finger. 
In applying the dam with this grasp the thumb of the 
right hand is placed on the lingual side of the tooth and 
the forefinger of the left on the labial, or buccal, side. 
Otherwise than this change of positions the motions with 
which the rubber is placed are the same as with the first 
grasp. This grasp is also suitable for the application of 
the rubber to the lower teeth of the right side as far back 
as the second bicuspid, the operator standing to the right 
and partially behind the patient. In this position the fore- 
finger of the left hand will be placed to the lingual of the 
tooth and the thumb of the right hand to the buccal. 

The third grasp is a modification of the second, in which 
the two hands are simply inverted, so that the thumb 
of the left is on the occlusal side of the rubber and the 
thumb of the right is on the lingual side. In every other 
way the grasp is the same. This is suited to placing the 
rubber on the lower teeth of the left* side of the mouth as 

4 



50 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

far back as the second bicuspid, the operator standing on 
the right and passing the left hand around the head. 

The fourth grasp is a complete inversion of the first. In 
this the thumbs are both placed on the gingival side of the 
rubber, and both forefingers on the occlusal side. The 
rubber is grasped with the thumbs opposite the first joint 
of the forefinger, or thereabouts. The ends of the fore- 
fingers come together over the hole to be used, not directly 
end to end, but in the form of a letter V, the finger-ends 
forming the angle. The rubber is now stretched so as to 
open the hole slightly while the finger-ends are close 
against its margins. Then it is carried over the tooth. 
stretching the rubber sufficiently by spreading the fingers 
apart, made to pass the contact points between the teeth 
one after the other by a slight sawing motion, and the 
finger-ends carried hard against the gingivae, one on the 
buccal side and one on the lingual side of the tooth. Then 
the grasp of the thumbs is released while maintaining 
the position of the fingers and the rubber allowed to draw 
around the tooth. If the rubber is felt to close on the 
finger-ends, which it will often do. and fail to close on 
the tooth, make a slight oscillating motion of the fingers, 
which will allow it to slip past them and hug to the tooth 
before removing the fingers. The rubber is now grasped 
anew and in the same way to be passed over the next tooth, 
being careful to place the finger-ends very close on either 
side of the hole to be used in each instance. 

This grasp is particularly suited to the upper bicuspids 
and first molars, the operator standing partially behind and 
above the patient. For this the head of the patient should 
be thrown well backward. Often, also, this grasp will be 
very convenient for placing the rubber on the lower bicus- 
pids and first molars, the operator standing to the right 
and in front of the patient. For this position the head of 
the patient should be upright. 

The fifth grasp is used especially for placing the dam 
on the second and third molars, or where it is necessary to 
reach far back into the mouth. In this the dam is first 
taken between the first and second fingers of each hand, 
with the forefingers and thumbs on the occlusal side. Then 



THE RUBBER DAM. 5 1 

the second, third and fourth fingers are closed, or nearly 
closed, and the dam grasped between the thumbs and sec- 
ond fingers, with the thumbs placed opposite the second 
joint of the fingers, or between the first and second joints. 
With this grasp stretch the dam a little and engage the 
two forefingers in it close on either side of the hole to be 
used, and with them stretch the hole open. It is generally 
necessary that the hole be opened sufficiently wide so that 
the tooth to which it is to be applied can be seen through it. 
Then carry it back into the mouth and pass it over the 
tooth with the forefingers, the one on the buccal, the other 
on the lingual, and engage one edge of the hole between 
the teeth, preferably the mesial first, and cause it to pass 
the contact by a sawing motion. When this has passed into 
the interproximate space throw the rubber over the distal 
surface, and if it is a second molar pass the contact in a 
similar way. Then carry each of the finger-ends hard against 
the gums on either side, buccal and lingual, of the tooth, 
and, holding them firmly in position, release the dam with 
the thumbs and second fingers. The dam will now draw 
around the tooth, or else it will be felt drawing on the 
ends of the forefingers. In the latter case a little motion 
of the ends of the fingers will allow the dam to slide by 
them and close firmly around the tooth. Then, and not till 
then, the fingers may be removed. The dam may now be 
grasped again in the same way and the forefingers engaged 
on either side of the next hole to be used and it brought 
over the next tooth, whether to the mesial or distal, in a 
similar manner. Notice particularly that the grasp on the 
rubber is to be released entirely at the end of its applica- 
tion to each particular tooth and grasped anew for the next. 
It is just as important to know how to remove the fin- 
gers from the rubber without pulling the rubber away with 
them after it has been placed on the tooth as it is to place 
the rubber over the tooth ; and I wish to emphasize the 
necessity of noting very carefully the manner of doing this, 
and draw attention strongly to the fact that the dam should 
be allowed to fully close around the tooth while the fingers 
are still pressed against the gums on its buccal and lingual 



52 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

sides. This applies to all grasps whatsoever that may be 
used in adjusting the rubber dam. 

In using the fifth grasp, the operator can use the full 
length of the forefingers for reaching back into the mouth 
and yet have full command of the rubber and readily place 
it on any tooth where the contacts can be passed with a 
sawing motion of the fingers : and in ordinary cases it will 
hold without the aid of a ligature while passing it over 
other teeth. Of course, there are many molar teeth around 
which the gums are so high that the rubber cannot be 
passed far enough onto the crown in this way for it to 
hold. There are also a good many tooth crowns so rounded 
that the dam must be forced actually to the gingival line 
and tied down with a ligature or held by a clamp before it 
can be induced to remain in place. With these grasps, 
however, everything can be done that it is possible to do 
with the unaided fingers. 

The Use of Ligatures in Adjusting: the Rubber Dam. 

There are many cases in which the rubber can not be 
forced between the contact points of adjoining teeth with 
the unaided fingers, and then it must be forced with the 
ligature. This is best done by an assistant. However, by 
careful practice one may learn to do it successfully alone. 
The ligature may be used with any of the five grasps. To 
accomplish this, wrap the end of the ligature on the little 
finger of the left hand and catch a part of its length in the 
same grasp with the rubber in the thumb and finger of the 
right hand, leaving just sufficient length between so that 
the ligature may be tightly drawn by a movement of the 
little finger on which it is wrapped. Bring this ligature 
over the contact to be forced beside the finger, or the 
thumb, of the left hand, at the same time that the rubber 
is stretched over the tooth. Then, by drawing with the 
little finger of the left hand and by the grasp with the right, 
the ligature is forced through, carrying the rubber before 
it. To get just the right length and adjustment of the 
ligature generally requires a little maneuvering in each 
individual case. The observant operator will see his way 



THE RUBBER DAM. 53 

dearer and be better able to avoid difficulties with each 
failure. 

In cases in which considerable force is required to drive 
the rubber past the contact, the grasp with the fingers is 
often insufficient. The ligature will slip in the fingers and 
the rubber will be stretched too much, and a general de- 
rangement of the position will result. In this case it will 
be necessary to arrange to use greater force. To do this, 
wrap the ligature on the little finger of each hand, noting 
carefully that the length between the fingers is just right. 
It will often be necessary to try this length a number of 
times before getting it to exactly suit the particular case. 
Then bring the ligature over the contact and under one of 
the fingers or thumb with which the rubber is forced down, 
and stretch down the rubber into the embrasure as far as 
possible ; then draw the ligature with the little fingers so 
as to tighten it on the rubber to hold it, and work the 
finger on the opposite side of the tooth onto the ligature, 
so that it may be forced on both sides of the tooth at the 
same time. The accomplishment of this last movement is 
the most difficult point, but it can generally be done after 
a few efforts, and then the operator has command of the 
situation. The rubber can be forced into the contact with 
all of the power of the fingers. After forcing the first con- 
tact the grasp of the rubber must generally be released, a 
second ligature wrapped on the fingers, the rubber grasped 
anew, and the second contact forced in the same way. This 
may now be continued until the rubber has been placed on 
a sufficient number of teeth. Generally, when the rubber 
has been forced past one close contact, this holds the 
rubber as a starting point and the rest is much easier of 
accomplishment. Very much of the difficulties of adjusting 
the rubber is relieved by having an assistant pass a liga- 
ture, or set a clamp in position in these difficult cases. 

Another method of avoiding the most serious difficulty 
in passing ligatures to force the rubber between teeth far 
back in the mouth is to set a special clamp on the tooth 
first, and then throw the rubber over the bows of the clamp. 
For this purpose the fifth grasp should be used, and the 
hole in the rubber should be a little larger than usual. The 



54 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

ends of the forefingers should be placed fully to the distal 
side of the hole, or so that its distal edge is fully between 
the finger-ends and upon their planter surfaces. Then it 
must be so stretched that the distal edge of the hole may 
be passed over the distal edge of the bow of the clamp, 
starting it first over its lingual portion and sweeping it 
around over the buccal portion, bringing the fingers down 
against the outer margins of the jaws of the clamp. Then 
release the rubber, and by a little careful motion of the 
fingers it is allowed to close around the tooth under the 
clamp. This part of the adjustment should be done entirely 
by the sense of touch, and should first be practiced out of 
the mouth for the purpose of learning the points to be 
made by this sense. These are : First, the ability to feel 
the position of the distal margin of the hole in the rubber 
on the fingers, and, second, by the sense of touch, bring 
this over the distal edge of the bow of the clamp. After 
this point has been passed, a sweep of the finger to the 
buccal over the bow of the clamp completes this part of 
the movement. Then, with the sense of touch the outer 
margins of the jaws of the clamp are found, and while the 
fingers are pressed against these the rubber dam is released 
with the thumbs. Then, as the rubber is felt to draw on 
the fingers, a little oscillating movement is made, which 
allows the rubber to close around the neck of the tooth 
under the jaws of the clamp. This is generally done easily 
and quickly when the particular relation of the fingers to 
the hole in the dam is appreciated. After this starting 
point has been secured it is not so very difficult to secure 
the rubber over the teeth mesial to it. When the rubber 
dam has been placed in this way on a second molar the 
rubber may catch on the cusps of the third molar, and re- 
quires to be pulled forward into position between the teeth ; 
or it may refuse to enter the contact between the teeth 
sufficiently to exclude moisture. In this case a ligature 
should be thrown around the clamp over the rubber dam, 
and with this the rubber is readily drawn into position be- 
tween the teeth. 

Some operators prefer to adjust the rubber over the 
bow of the rubber dam clamp after the clamp has been 



THE RUBBER DAM. 55 

fixed in the clamp forceps, and before the clamp has been 
fixed on the tooth. Then the rubber dam is so folded to- 
gether as to be as little as possible in the way, and the 
clamp set upon the tooth. Then, when the forceps are re- 
moved, the dam slides partly into position. It may then 
be unfolded and adjusted to the face of the patient, and can 
then be worked under the jaws of the clamp with the flat 
curved burnisher and be made to exclude moisture. It 
is then adjusted to the teeth mesial, to the one upon which 
the dam clamp has been placed. This plan may be made 
very successful, but is more difficult and takes more time 
than that by throwing the rubber over the clamp after it 
is placed on the tooth. 

Passing the contact with ligatures should be done with 
much care, for if it is allowed to snap onto the gums it 
will often induce considerable pain and do the patient a 
real injury by cutting into the tissues. To avoid this, 
always catch the ligature very close to the tooth on both 
the buccal and lingual sides. This will prevent that forcible 
snap onto the sensitive tissues that is sure to occur if this 
precaution is not observed. 

In many cases a ligature must be tied over the rubber 
to hold it in place, or to force the gums sufficiently to the 
gingival to expose the gingival margin of the cavity. In 
doing this the ligature should be carefully forced close to 
the gingival line and tightly drawn with a surgeon's knot. 
Generally it is not necessary to tie ligatures on every tooth 
over which the dam is placed. Often when ligatures seem 
necessary, if the rubber is just drawn well down the liga- 
ture may be at once removed and the rubber will remain 
in position. Ligatures are often painful, and when the re- 
sults can be well accomplished without them they should 
not be used. 

Often there will be difficulty in adjusting the ligature to 
the lingual side of the incisors with the unaided fingers. 
The shape of the lingual surface causes it to slip ofT. In 
these cases the ligature should be thrown loosely around 
the tooth and the first half of the knot formed, but before 
it is drawn up the flat-curved burnisher should be passed 
to the lingual of the tooth inside the loop of the ligature 



56 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

and carried to the gingival line, and so inclined that when 
tne ligature is drawn with the other hand it will be guided 
to the right position. Then the burnisher may be removed 
and the knot closed. This burnisher is useful in many 
positions as an aid in the adjustment of ligatures. 

In tying ligatures about the teeth, the first half of a 
surgeon's knot should first be formed and tightly drawn. 
In doing this the ligature should be grasped as close to the 
knot as practicable, and held close against the teeth, both 
to the mesial and to the distal. If the ligature is over the 
bicuspids or molars catch the distal end of it over the end 
of the forefinger of one hand and force it to the distal while 
pulling the mesial end with the other hand. If the ligature 
has been well waxed, the first half of the knot will not 
slip or loosen ; but it must not be pulled or disturbed in 
the least while forming the other half of the knot. Let 
the ends fall perfectly loose while forming the second half 
and work it up carefully until it is just right and then draw 
it tight at a single pull, again keeping the fingers close 
against the arch, both to the mesial and distal. A ligature 
tied in this way will always be tight around the tooth. 

Rubber=Dam Clamps 

The question of rubber-dam clamps is always a trouble- 
some one. Nothing is entirely satisfactory in all positions. 
The selection on the list is as good for the purpose as can 
be had. With them all can be done that clamps will do. 

In filling cavities in the bicuspids the rubber should be 
secured on the molar tooth distal to them with a rubber- 
dam clamp. The bow of the clamp holds the rubber out of 
the way and gives space and a better view of the field of 
operation. In excavating and filling cavities in the molars 
this is still more necessary. Whenever practicable the 
ciamp should be placed upon the first molar for operations 
on the bicuspids, and on the second molar for operations 
on the first molar. Generally, in operations on the second 
molar not involving the distal surface, a clamp with a bow 
standing well to the distal should be placed on the same 
tooth in order to avoid the difficulty of placing the dam on 
llic third molar. Rubber-dam clamps on the bicuspids are 



THE RUBBER DAM. 5/ 

not permissible at all except in cases where the molar 
teeth are missing; and even then they are of doubtful use- 
fulness, and are so unsteady as to cause the patient much 
annoyance, and often considerable pain. 

In buccal and labial cavities, that approach near to, or 
pass beyond, the gingival line, the special clamp should be 
used on the molars and the Hatch clamp on the bicuspids 
and front teeth. Except in the most difficult cases, the 
special clamp will answer the purpose if the rubber, after 
being placed on the tooth, is drawn well away from the 
buccal and the clamp applied, or if the clamp is put on 
first and the rubber passed over it. When the Hatch clamp 
is applied to the front teeth with labial cavities, the rubber 
must be drawn well away from the labial surface and the 
points placed in position and the set-screw made tight. 
Then the rubber may be allowed to draw tightly around 
it, and is fairly certain to exclude moisture perfectly. For 
this purpose the hole in the rubber should be cut a little 
larger than usual. 

When the Hatch clamp is to be used on any of the in- 
cisors or cuspids in order to expose the gingival margin of 
a labial cavity that is close to the gingival line, no ligature 
should be tied on the tooth. No effort should ever be made 
to expose the gingival margin of such cavities by use of 
the ligature, for the reason that the cavity margin is so 
generally further rootwise than the attachment of the gum 
tissue on the proximal sides of these teeth. This is made 
so by the curve of the gingival line as it passes around 
the incisors and cuspids. Therefore such use of the liga- 
ture causes unnecessary pain and is apt to cause permanent 
injury by tearing the. gum tissue away from the tooth on 
its proximal sides. 

With the most skilful, some impossible cases occur with 
any and all of these instruments. .Then resort must be had 
to holding the dam in position with an instrument while 
performing the operation with the other hand. This is 
difficult, but practicable. The best instrument for this 
•purpose is a straight shaft with a broad flat point cut in 
the form of a fork, or a V-shaped notch. 

Often in proximate cavities, where the gingival wall is 



58 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

very difficult to reach, the rubber may be forced into posi- 
tion and held with a matrix, or the matrix may be placed 
first and securely tied and the rubber applied over it. 
Sometimes a similar device will accomplish the same upon 
buccal surfaces. 

When the operation is completed, great care should be 
had to remove all ligatures before removing the rubber, 
for if the rubber is pulled away with a ligature on, a ring 
of rubber will sometimes be torn away and remain around 
the neck of the tooth unobserved, and do great damage 
before the cause is discovered. When the contacts between 
the teeth are close, or when gutta-percha fillings have been 
placed to seal in treatments, the rubber should be drawn 
to the buccal or labial, and the septum passing between the 
teeth cut before removing the rubber. This will avoid the 
danger of leaving bits of rubber dam hanging between the 
teeth or of disturbing a soft filling. Finally, when the 
rubber has been removed, the gums should be well kneaded 
with the fingers, while being flooded with warm water 
from the syringe. The gums have been compressed and 
the circulation interfered with, and this will clean the 
parts and start the blood into full activity and prevent 
the severe soreness that is so apt to follow. 

The Enamel. 

The structure of the enamel is of such importance in 
its relation to the preparation of cavities for filling that it 
requires special study. It is difficult to so prepare speci- 
mens of the enamel that they show its structure well, and 
when the specimens are well prepared it requires a large 
amount of study to gain that intimate knowledge of it that 
is necessary to the most intelligent practice in filling opera- 
tions. 

The enamel, when examined macroscopically, -appears 
as a very hard, vitreous body, white, or a bluish-white, 
very dense and brittle, in which no traces of structure can 
be determined. It cuts with much difficulty, and is much 
inclined to chip and crumble. If, however, it is examined 
with a good hand magnifying glass, certain striations can 
be observed that give a suggestion of histological structure. 



THE ENAMEL. 59 

Although the enamel seems to be opaque, or, at most, 
translucent, by ordinary examination, it is found to be 
almost as transparent as glass when ground into thin sec- 
tions. When so prepared, very little of the structure can 
be seen with the microscope usually, without some prepara- 
tion that will cause its histological elements to appear. 
It is largely for this reason that so little is seen of the 
structure of enamel in the sections ordinarily prepared for 
microscopic observations. 

Histological Characters of the Enamel in Relation to 
the Preparation of Cavities. 

Enamel is composed of rods or fibers cemented to- 
gether by an intervening cement substance. These rods 
and cement substance are very nearly of the same density, 
so that when examined in the perfect state the enamel 
seems to be almost homogeneous, or without special struc- 
ture. In the most perfect specimens of enamel only a 
striation suggesting structure can be seen. It has been 
learned, however, that the cement substance between the 
rods by which they are united dissolves more readily in 
acids than the rods themselves. We may avail ourselves 
of this fact, and partially isolate the rods by solution of 
the cement substance with very dilute hydrochloric or 
lactic acid, and in that way obtain good views of them. 
We cannot, however, carry this solution very far, for the 
reason that the rods will also be dissolved, and the whole 
tissue disappear. Still, by working carefully with very 
dilute acids, good fragments of the rods may be obtained. 

The enamel rods seem to be made up of globules or 
little balls pressed together in a single row or line, forming 
the rod. One can readily copy this formation by taking 
small balls of soft clay and pressing one upon the other, 
forming a rod. In some enamel these globular forms are 
very prominent in the apparent make-up of the rod, while 
in some other specimens these globules are so perfectly 
fused together and smoothed as to almost disappear; we 
then have a smooth enamel rod. This latter is rather the 
exception than the rule. 

The enamel rods are stronger than the cement sub- 



60 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

stance, so that in any attempt to break up or cut the enamel 
it is inclined to split along the length of the rods. Then, 
since the enamel is very hard and difficult to cut, a knowl- 
edge of the direction of the rods becomes of first im- 
portance in any attempt to form cavities in teeth. These 
rods, while hard to cut, are, when they are parallel, very 
easy to split apart. Indeed, much of human enamel will 
split almost as easily as straight-grained pine, if the force 
is applied in just the right direction. This is because the 
cementing substance that cements the rods together is 
much weaker than the rods themselves. In other speci- 
mens of enamel the rods, instead of lying parallel with 
each other, are very much interwoven and twisted to- 
gether; so much so, indeed, as to prevent them being 
readily split apart. This enamel, instead of splitting like 
straight-grained pine, is more like the pine knot, which 
is very difficult to split or cut, as compared with the 
straight-grained wood. Formerly it was supposed that 
this difference in the enamel to cutting instruments was 
due to a greater amount of lime salts, or the hardening 
element. We have learned in recent years, however, that 
this is not the case. The one contains no greater propor- 
tion of lime salts than the other and will not resist decay 
any better. But the difference is due wholly to the differ- 
ence in the relative interlacing of the enamel rods. 

This interlacing or twisted form of enamel is usually 
confined to the inner half of its thickness. While in the 
(niter half of the enamel the rods are parallel and will split 
apart readily, the rods of the inner half are interwoven or 
twisted in such a way as to prevent splitting. Therefore, 
when a chisel or enamel hatchet is applied for the purpose 
of splitting it off it will, if supported by sound dentin, split 
but about half way, and the remaining half of the thickness 
is removed with great difficulty. It is then almost a neces- 
sity that we undermine this by cutting away the dentin 
from beneath it, after which we may break it down quite 
readily. 

The enamel rods are almost always parallel with each 
other in the outer half or near the surface of the enamel. 
This fact you should observe carefully, for it is of the ut- 



THE ENAMEL. 6 1 

most importance in the preparation of the enamel margins 
of cavities. All that we have said of the splitting apart of 
The enamel rods applies with all of its force to this outer 
portion of the enamel, no matter how much the rods may 
be twisted in the deeper portions, and for this reason the 
enamel margins of cavities should be so prepared that no 
portion of the cavo-surface angle will present short ends 
or rods unsupported ; that is, the enamel wall should be 
parallel with the length of the rods, and the bevel of the 
cavo-surface angle should cut off the ends so that there 
may be no loose ends of rods upon the surface to fall away 
while packing gold or after finishing the filling. This may 
readily be accomplished if we know the direction of the 
enamel rods. 

The direction of the rods may be known, first, by ob- 
taining a good general knowledge of their course by the 
study of prepared sections of enamel ; second, by observing 
the direction of cleavage during the preparation of cavities. 
By the term cleavage we express the tendency of a sub- 
stance to split or separate in given directions. The direc- 
tion of cleavage is the direction in which it splits most 
readily. Therefore, for our purposes the terms cleavagf 
and splitting are practically synonymous. 

It may be stated as a general rule that the direction of 
the enamel rods is from the center of the crown of the 
tooth toward the surface. Everywhere on the crown of 
the tooth the ends of the enamel rods present to the sur- 
face. Over the greater portion of the crown the direction 
of the enamel rods is perpendicular to the surface, but in 
every tooth there are certain portions in which the enamel 
rods approach the surface at a more or less considerable 
inclination. 

If we draw a line around the crown of a molar or bicus- 
pid tooth in the middle of its length and examine the 
enamel rods in that section we will find them everywhere 
very nearly perpendicular to the plane of the surface. If 
Ave move, now, gradually, toward the cusps of the tooth 
we will find the direction of the enamel rods progressively 
leaving the perpendicular and inclining toward the cusps. 
This inclination becomes continually greater, until when 



62 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

the point of the cusp is reached the direction of the enamel 
rods is parallel to the length of the cusp, or, in other words, 
the direction of the rods is perpendicular to the surface of 
the tip or point of the cusp. 

If from this line around the crown of the molar or 
bicuspid in the center of its length we approach one of the 
marginal ridges of the occlusal surface, we will also find 
the direction of the enamel rods inclining toward the mar- 
ginal ridge in such a way that as we pass over the mar- 
ginal ridge the direction is so changed that the rods stand 
perpendicular to the occlusal surface. 

If the attempt be made to prepare a cavity upon an 
axial surface of one of these teeth for filling, and this cavity 
approaches a cusp or a marginal ridge, the enamel wall 
must be inclined outward (or toward the occlusal) very 
greatly, or else short ends of enamel rods will be left at 
the surface. And if inclined enough to prevent this, the 
filling material will be so thin at its margin that it will not 
have sufficient strength. These facts forbid us laying: 
enamel margins near the occlusal margins of the axial 
surfaces of the teeth. 

If now, we proceed from the center of the length of the 
crown of the molar or bicuspid toward the gingival line, 
we will find the direction of the enamel rods again deviat- 
ing from the perpendicular and inclining toward the gin- 
gival line. This inclination is much less in extent, how- 
ever, but more variable than that found in passing toward 
the marginal ridges of the occlusal surfaces. The inclina- 
tion at the gingival line is usually about six centigrades, 
often less, and the greatest that I have observed has not 
been more than ten centigrades. An inclination of six 
centigrades is readily overcome by inclining the enamel 
wall, or even twelve centigrades inclination of this part 
of the enamel wall can readily be made and the filling 
material be sufficiently strong for the locality. 

On examination of the occlusal surface of a molar or 
bicuspid we find a tendency of the enamel rods to incline 
somewhat toward the pits and grooves, and especially do 
they incline toward open pits or fissured grooves. If the 



THE ENAMEL. 63 

grooves are well closed and shallow, there will be less 
inclination toward them. 

As we pass from the pits and grooves toward the cusps 
the direction of the rods first becomes perpendicular to the 
surface and then begins to incline toward the cusps, and 
when we arrive at the point of the cusps the direction will 
be perpendicular to the surface at the immediate point of 
the cusp. Or, if we follow the direction of the rods pass- 
ing from the fossae of the occlusal surface to the marginal 
ridges, mesial and distal, we find the direction of the rods 
first deviating from the perpendicular toward the center 
of the fossae, but as we pass toward the marginal ridges the 
deviation is toward the marginal ridges, until, when we 
arrive near the crest of the ridge, the direction of the 
inclination is decidedly toward the ridge. 

Therefore, in the preparation of cavities in the occlusal 
surfaces of these teeth the enamel wall may be cut per- 
pendicular to the general plane of the occlusal surface, so 
long as the enamel margin does not approach too closely 
to cusps or the marginal ridges, for a slight bevel of the 
cavo-surface angles will insure a solid margin without any 
short ends of rods. But if the cusps or the marginal ridges 
are closely approached the inclination of the enamel wall 
should be toward the ridge and the cavo-surface angle 
beveled rather more strongly in order to insure the removal 
of all short ends of enamel rods, and to secure a firm 
margin. 

In the incisors and cuspids, if we draw a line around 
the crown at the junction of the middle and gingival third, 
we will find the enamel rods perpendicular to the surface 
upon the mesial, distal and labial surfaces, and generally 
nearly so upon the lingual surface. In these teeth the 
direction of the enamel rods at the junction of the middle 
and gingival third of the lingual surface is very variable, 
because of the differences of the prominence of the linguo- 
gingival ridge and the depth of the grooves of the lingual 
surface. In cases in which the linguo-gingival ridge is 
prominent and the grooves deep, or fissured, there will be 
a strong inclination of the enamel rods toward the grooves. 
If, on the other hand, this surface is smooth and even, with 



64 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

the grooves perfectly closed, so as not to be apparent, the 
direction of the enamel rods will be perpendicular to the 
surface. 

As we pass from the junction of the middle and gingival 
third of the crown toward the incisal margin of the lingual 
surface, the inclination of the enamel rods is more and more 
toward the incisal. At the junction of the middle and 
incisal third the inclination is from six to twelve centi- 
grades, and in the incisal third it often is fifteen or eighteen 
centigrades before the incisal edge is reached. This very 
strong inclination of the enamel rods toward the incisal 
upon this surface renders it exceedingly difficult to make 
good margins if the marginal lines of the cavity approach 
nearer the incisal edge than the junction of the middle 
and incisal thirds of the crown. If the cavo-surface angle 
of the enamel is beveled enough to remove all short ends 
of enamel rods the filling material becomes too thin to 
stand well. This is the reason we so frequently see imper- 
fect margins when the marginal lines of fillings have been 
laid in this position. 

On the labial surface of the incisors and cuspids, the 
direction of the enamel rods is generally about perpen- 
dicular to the surface of the junction of the middle and 
gingival third, and as the incisal margin of the surface is 
approached there is a gradual inclination toward the 
incisal. This change is slow in the middle third, so that 
it is rarely more than six centigrades at the junction of 
the middle and incisal thirds. In the incisal third the 
increased inclination to the incisal is much more rapid, so 
that upon the incisal edge the direction of the enamel rods 
is parallel to the long axis of the tooth. These directions 
of the rods must be taken into account in any case in 
which the marginal lines of labial cavities approach the 
incisal margin of the surface. Fortunately, such cavities 
are rare. 

On the mesial and distal surfaces the direction of the 
enamel rods is generally perpendicular to the surface 
throughout the middle third of the length of the crown. 
In the incisal third an inclination toward the angle begins. 
The extent of this is quite variable. The rule is that the 



THE ENAMEL. 65 

more acute the angle the closer the angle is approached 
before the inclination of the rods toward the angle becomes 
pronounced. Therefore, the distal angle being more 
rounded the inclination of the rods toward it begins further 
from the angle upon the distal surface, but often approaches 
the angle quite closely upon the mesial before the inclina- 
tion becomes great. For this reason cavity lines in mesial 
surfaces may approach safely quite close to the incisal 
angle if the enamel is well supported by sound dentin. In 
the distal surfaces much more care must be exercised in 
laying cavity lines close to the incisal angle, for the reason 
that if the enamel wall is inclined enough to give a good 
cavo-surface angle the edge of the filling is likely to become 
too thin to stand well. 

In following the inclination of the enamel rods around 
the incisors and cuspids in the circumferential direction, 
we find them generally standing perpendicular to the sur- 
face. A notable exception to this is the approach to the 
mesial and distal marginal ridges on the lingual surface 
and over the lingual marginal ridges. Here the enamel 
rods incline somewhat toward the marginal ridges, but in 
passing over these ridges their direction or inclination 
changes rather suddenly. For this reason this becomes 
rather a dangerous point in the preparation of proximate 
cavities in the incisors. When the marginal lines of these 
proximate cavities reach to the lingual marginal ridge, it 
is rarely safe to leave any of the ridge remaining, because 
of the very uncertain direction of the enamel rods. Espe- 
cially is this true of lateral incisors, in which the curve of 
the ridge is often very abrupt. While this ridge is very 
strong in the perfect tooth, it becomes very frail when 
its support on either side has been destroyed, and the 
only safe course seems to be to cut it away sufficiently to 
be certain of the direction of the enamel rods upon the 
margin formed. The rounding of the labio-mesial or labio- 
distal angles is not so abrupt, and the enamel rods usually 
hold closely to a direction perpendicular to the surface, so 
that good margins can be made at any point by observing 
carefully the form of the tooth and the enamel cleavage. 

In passing toward the gingival line from the junction of 



66 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

the middle and gingival third of the length of the crown, 
the inclination of the enamel rods changes more and more 
toward the gingival. This varies considerably in different 
specimens ; generally it is not much more than six or eight 
centigrades at the gingival margin of the enamel, but in 
some specimens it is ten or twelve centigrades. This calls 
for extreme care in beveling gingival cavo-surface angles 
in cavities that approach close to the gingival line. 

How to Study the Direction and Inclination of the 
Enamel Rods. 

The first studies of the enamel rods should, of course, 
be made by grinding sections and studying these with the 
aid of the microscope, and in lantern illustrations. But 
when a fairly good idea of the structure has been obtained 
in this way it is better to continue the study by noting 
carefully the cleavage of the enamel while operating at the 
chair. In preparing cavities one is handling the enamel 
all the time, and by noting the direction of the cleavage 
and remembering that this cleavage follows the length of 
the enamel rods, may be continuously studying their direc- 
tion in different positions upon any and all of the teeth. 
This study, when pursued for some time, enables an 
operator to so place his instruments as to split off the 
enamel easily in opening cavities, which is of immense 
advantage in this work, as he will do it easier and quicker. 
The operations will also be greatly improved because of 
more perfect preparation of the enamel margins. He will 
come to know very perfectly the direction of the rods, and 
the proper inclination of the enamel Avail in all positions. 

One soon learns to feel for the direction of the enamel 
rods with his cutting instruments and to take advantage of 
the cleavage in cutting the enamel, and then readily feels 
this in the formation of the enamel Avail and its cavo- 
surface angle, and knows when his enamel margin is firm 
and strong. Carry on the study at the chair and become a 
rapid and strong operator. 

The shaA'ing up of the enamel in forming the enamel 
Avail should be looked to with great care. Those points at 
which the enamel rods are more or less broken apart will 



THE ENAMEL. 67 

generally appear a little whitish, and in pushing a sharp 
edge lightly along them the loosened rods are easily dis- 
lodged in what appears as a fine powder. By continuing 
this shaving motion the enamel wall will become clear, 
and have a firm, vitreous appearance. This condition of 
the enamel wall should always be obtained in finishing the 
preparation of the cavity. 

In the study of the enamel in sections and on the 
screen, it has been seen that the lines of the grooves are 
weak lines on account of the imperfect fusion of the enamel 
plates in coming together during development. This is 
true even in those grooves that are most perfectly closed. 
But in very many cases they are imperfectly closed, so 
that along these lines the enamel has no strength. 

It should, therefore, be the rule, when in the prepara- 
tion of a cavity the marginal lines must approach near a 
groove, to cut to the groove or past it. 

This rule should be regarded as applying in all posi- 
tions upon the teeth if the cavity margin is parallel, or very 
nearly parallel, with the groove. For instance, I will men- 
tion that in preparing large cavities in the distal surfaces 
of upper molars the disto-lingual groove is often ap- 
proached. In any such case cut to the groove until it has 
passed over the ridge to the lingual surface, when its direc- 
tion is more to the mesial, and then break away from it 
rather suddenly, forming a kind of step, if the enamel of 
this portion of the lingual surface is well supported by 
sound dentin. 

If the mesio-buccal angle of a molar is so decayed as 
to make the removal of a considerable part of it necessary, 
cut to the buccal groove, for if this is not done the inter- 
vening portion of enamel is very likely to break away. 

The same rule applies to the triangular grooves of the 
bicuspids that pass to the buccal surface to the mesial and 
distal of the buccal cusps. If in any case the angles of these 
teeth are so injured that the cavity lines should approach 
near these grooves, cut to the grooves. 

In any case in which the angle of an incisor must be 
removed, cut to the labial groove, whether it be mesial or 
distal. This is for the reason that the lines of the grooves 



68 THE TECHNICAL PROCEDURES IN TILLING TEETH. 

are weak lines, and the enamel is likely to break along* 
these lines. 

These cases will sufficiently illustrate this rule. 

Excavation of Cavities by Classes. 

Xote. — The determination of the conditions calling for 
rilling operations is largely dependent upon pathological 
processes. As it is the intention to confine this book as 
strictly as possible to the technical procedures of filling- 
operations, these pathological processes will not be dis- 
cussed. Here we can only take note of the physical con- 
ditions presented by individual teeth, leaving pathological 
processes related to them to be taken up at another time. 



Class i. — Cavities beginning in structural defects in the 
teeth, as pits and fissures, — These occur in the occlusal 
surfaces of the molars and bicuspids, in the occlusal half 
of the buccal surfaces of the molars, or in the buccal pits, 
more rarely in the lingual portion of the disto-lingual 
groove of the upper molars, and in the lingual surfaces of 
the upper incisors ; most frequent in the laterals. 

The primary physical condition leading to the location 
of caries in these positions is a fault, or imperfection in the 
enamel — an imperfect closure of the enamel plates — which 
leaves an opening of more or less depth as a pit or fissure, 
and it is in these that decay starts. The surface of the 
enamel in the immediate neighborhood of these is fully 
exposed to the friction of mastication and is kept well 
cleaned. For this reason there is no disposition to the 
spreading of the carious process upon the surface of the 
enamel. Therefore, these cavities all belong to the class 
which do not require extension of the cavity outlines for 
the prevention of the recurrence of decay. All the exten- 
sion that is necessary is such cutting away of the cavity 
walls as will fully uncover the carious area and present a 
surface upon which a good, smooth finish of the filling 
can be made. In order that this good, smooth finish may 
be made, it is necessary that all sharp grooves connecting 
with the cavity be cut out to a point where the enamel is 
-ufriciently level. 



EXCAVATION OF CAVITIES BY CLASSES. 69 

As a primary study of the conditions presented in this 
class of cavities the student should select a number of 
teeth from the collection of extracted teeth and open the 
pit cavities. This is best done, when a suitable lathe can 
be had, by sawing the tooth through the central area of 
decay with an aluminum disc charged with carborundum 
powder in glycerine. When this cannot be had much good 
work can be done by filing, or grinding away one-half of 
the tooth, retaining the other half with its exposed cavity 
for study. Much familiarity with the conditions that will 
be presented by these cavities as they occur in the mouth 
may be obtained also by opening and forming these as it 
would be done in the mouth in preparation for filling. 
Enough of this work should be done to render the student 
familiar with the directions and the extent in which decay 
burrows under the enamel in the occlusal surfaces, and 
also other pit cavities. 

Pit Cavity in Central Fossa of an Upper First Molar No. 1. 

Description. — Upon examination a small pit in the 
enamel is found and the point of the exploring instrument 
passes through it into the dentin, which seems to be soft- 
ened, showing that caries has begun. The surface of the 
enamel about the pit is clear and clean. The buccal groove 
is deep and sharp, but the mesial and distal grooves are 
shallow, fairly smooth, and well closed. 

Procedure. — A round bur, A millimeters in diameter, 
in the engine, is placed in the pit while in rotation and 
fairly strong pressure applied, while the hand-piece is 
swayed to and fro. In most cases the bur will cut througli 
the enamel and enter the cavity within a few seconds. If 
it does not do so promptly, it should be removed for a 
moment and allowed to cool — for heat will develop quickly 
— and then reapplied in the same manner. This should 
be repeated until the bur passes through the enamel and 
enters the softened dentin. Immediately this occurs, the 
bur should be removed from the hand-piece and a bur, I 
millimeter in diameter, chosen. This is passed through 
the opening into the dentin in the same way, thus enlarg- 
ing the opening in the enamel. This is then exchanged for 



70 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

a larger bur, ii*<$ millimeters in diameter, which is also 
passed through the opening. This completes the use of the 
round bur, and it is the only use made of it in excavating 
cavities. An examination should now be made with a 
curved explorer to determine more nearly the extent of the 
decay in the dentin. In case no softened dentin extending 
laterally under the enamel is found, the rubber dam should 
be applied and an inverted cone bur, equal in size with 
the last round bur used, should be introduced, and with its 
square end the remaining decay should be removed, and 
the floor, or pulpal wall, of the cavity made flat. Xow, with 
hoe 12-5-6 used as a chisel (straight chisel 10 or binangle 
chisel 10-6-6 may be substituted), the enamel is chipped 
away along the buccal groove as far as it will readily 
split oft. Then an inverted cone bur, & millimeters in 
diameter, is passed into the cavity and made to enter the 
dentin just beneath the dento-enamel junction toward the 
buccal groove, and slowly drawn to the surface of the 
enamel. It is then entered again at the same point, and 
this motion repeated, making cut after cut, following the 
line of the groove, until the groove has been opened to a 
point where it is sufficiently shallow, or the surface of the 
enamel is sufficiently level for a good finish of a filling to 
be made. Often it will be necessary to follow this groove 
to the crest of the marginal ridge. This done, chip away 
the mesial and distal walls of the slot formed, with straight 
chisel 15 or 20, sufficiently to remove the inclines of the 
buccal groove, after which pass a large inverted cone, or a 
fissure bur (ii 2 o millimeters), through the slot, and make 
its floor square and flat, and smooth up the walls. 

A very careful examination should now be made of all 
parts of the walls of the cavity. If any softened dentin is 
found, the enamel should be chipped from over it with hoe 
12-5-6 or chisel 10, the softened area removed and the pul- 
pal wall of the cavity squared out to the increased area. 

The outline of the cavity should now be re-examined 
to see whether every part of the margin is sufficiently 
level to permit a good finish of the filling when this has 
been placed, and if irregularities occur that would prevent 
a smooth finish, the cavity must be sufficiently extended 



EXCAVATION OF CAVITIES BY CLASSES. 7 1 

to obtain conditions that will allow a good, smooth finish 
of all parts of the margin to be made. 

The finish of the enamel wall is now to be made by 
careful paring or planing with a sharp chisel. So far as 
possible the movement of the edge of the chisel should be 
in the direction of the length of the margin, or around the 
cavity. In such a cavity as this, both the dentin and 
enamel walls may be perpendicular and the opposing walls 
parallel. The enamel rods will be inclined toward the 
cavity in every part, and no outward inclination of the 
enamel walls is necessary. The cavo-surface angle of the 
entire margin should be slightly beveled to diminish the 
danger of fracture in placing the filling material. In such 
a cavity no starting points for beginning the filling are 
required, and no further preparation for retention of the 
filling is necessary, except to see that the opposing walls 
are parallel. 

Variations. — It will often happen that in a cavity of 
this description a considerable area of decayed dentin will 
be found beneath the enamel after the burs have been 
passed through into it. In this case the overhanging 
enamel must be chipped away with hoe 12-5-6 or chisel 10 
or 15, until sound dentin is reached in every direction. 
When this has been done, the remaining portion of the 
buccal groove should be cut out as described, first com- 
pleting the outline of the cavity. Then, if the area has 
become considerable, the remaining decay is best removed 
with spoons 1 5-8- 12 or 20-9-12, as may best suit the size 
of the cavity. Enter the blade beneath the softened 
material, close against the enamel wall at the lingual or 
buccal side, and force it with a strong thrust in a curved 
direction to the other side of the cavity ; two or three 
strokes well made should be sufficient. Then square up the 
pulpal wall so that its angles with the surrounding walls 
are sharp and definite, using hoe 12-5-6 or, in some posi- 
tions, hoe 12-5-12, with a scraping motion. In many cases 
this will be as conveniently and accurately done with a 
square-ended fissure bur, lie millimeters in diameter, or 
with the inverted cone bur. In this use of the bur, the 
shaft should be held parallel with the long axis of the 



/2 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

tooth, so that the square end of the bur will cut the pulpal 
wall of the cavity flat and make its angles with the sur- 
rounding walls sharp and definite. Finish the enamel wall 
and cavo-surface angle the same as before. In many cases 
the mesial groove will be so sharp and deep that it will 
require cutting out well toward the mesial marginal ridge. 

Pit Cavity in Central Fossa of Upper First Molar No. 2. 

Description. — The pit is open so that the exploring 
instrument readily passes in. giving room to be turned 
about, revealing a considerable decayed area ; some dis- 
coloration shows through the enamel. 

Procedure. — Begin the excavation by chipping away the 
overhanging enamel with straight chisel 15. Or, if the 
orifice in the enamel is still very small, begin with straight 
chisel 10, and use the 15 later. This may be done by hand 
pressure, but mallet pressure is much better. In using 
mallet pressure for the purpose of chipping enamel the 
instrument should be held firmly between the fingers with 
the third finger rested against the adjoining teeth. The 
instrument so held should be placed lightly on the enamel 
near the margin of the cavity and so directed as to throw 
the chips into it. A single quick, sharp stroke should be 
used. The grasp upon the instrument should be suffi- 
cient to prevent the stroke of the mallet from thrusting it 
into the depths of the cavity and causing pain by striking 
its more sensitive parts. Continue this chipping as far as 
the enamel can be readily cut in this way, or until sound 
dentin is found supporting the enamel at every point. 
Xow look carefully to the relations of the outline of the 
cavity to the surface, and proceed at once to cut out any 
grooves that will interfere with a perfect finish of the 
filling. Xow take hatchet 8-3-23, or, if the opening into the 
cavity is too small for this, take hatchet 6-2-23, and sweep 
its (tdgc around the dentin wall of the cavity with a few 
\igorou- -trokes, loosening up and partially removing 
the softened material from them, and see whether or not 
there are some points at which decay extends beneath the 
enamel, if such are found, clip the enamel from over them 



EXCAVATION OF CAVITIES BY CLASSES. 73 

and perfect the cavity outline. At this point the rubber 
dam should be adjusted. 

The next step should be to square up the dentin walls. 
If there is a considerable mass of decay obscuring the 
cavity, it may be first removed roughly by a few vigorous 
strokes with spoons 20-9-12. 

In squaring up the dentin walls a square-end fissure 
bur (lid millimeters) may be used in cases in which this 
may be brought parallel with the long axis of the tooth, 
which can generally be done in the occlusal cavities in the 
first molars and bicuspids. This is placed with its end 
upon the pulpal wall, and, while rotating, pressed laterally 
against one of the surrounding walls, and carried around 
the whole cavity in a series of cuts. This will square up 
the surrounding dentin walls to the enamel walls, and its 
square end will leave the pulpal wall flat, and its angles 
with the surrounding walls sharp and definite. This is to 
be taken as the plan of squaring up the surrounding and 
pulpal walls (and axial walls in buccal and labial cavities) 
when burs are used for that purpose. 

In doing this, care should be had not to continue any 
single cut so long as to develop considerable heat. Often 
much unnecessary pain is produced, and occasionally 
serious injury done to the pulp of the tooth by the heat 
developed by rapidly rotating burs. Also care must be 
had as to possible unnecessary exposure of the horns of 
the pulp of the tooth. In very deep cavities it may be 
best not to square up the whole central depth of the cavity, 
because of danger to the horns of the pulp, but to cut a 
shelf, so to speak, around the periphery to form the prin- 
cipal seat of the filling, leaving the central part of the 
cavity deeper. This deeper portion should then be freed 
of softened material with the spoon excavators. In no 
case should any decayed and softened material be left in 
the deeper parts of the cavity. It is better to expose the 
pulp of the tooth than to leave it covered only with 
softened dentin. 

In many cases the squaring up of the surrounding 
walls, and flattening of the pulpal wall, may be more easily 



74 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

done with the hoe 12-5-12, or 12-5-6, used with a scraping 
motion, than with the bur. 

When the walls of the cavity have been squared up, 
and the angles of the pulpal wall, with the surrounding 
walls, made sharp and definite, and all carious material 
removed, the enamel walls may be planed to form, and 
made smooth in every part. Unless the enamel walls 
approach very close to the marginal ridges, they may be 
in the same plane with the dentin walls, or parallel to the 
long axis of the tooth. But if they do approach closely to 
the marginal ridges, the enamel rods will be inclined toward 
the ridges, and the enamel wall must be similarly inclined 
to be in correct form. This may always be discovered 
by noting carefully the direction of the cleavage of the 
enamel while chipping it away, and the inclination of the 
enamel wall should be made to correspond with the enamel 
cleavage. When the enamel wall is in correct form and 
planed smooth, the cavo-surface angle must be slightly 
beveled in every part. This bevel should not extend to 
more than one-fourth the thickness of the enamel, and 
often should be much. less. 

Generally such cavities need no convenience points for 
starting fillings, but when large, and the operator feels 
that slight convenience pits will aid him, there is no spe- 
cial objection to their use. They should be placed in the 
distal portion of the cavity. Parallel walls and a flat 
pulpal wall as a seat, or a good strong peripheral ledge in 
very deep cavities, gives perfect anchorage. No under- 
cuts are required. All of this done, the cavity should be 
swept free of chips and fine dust, and is ready for filling. 
The use of chip-blower should be sufficiently frequent and 
thorough to keep the cavity free from cuttings, and the 
whole field of operations cleared of debris during all parts 
of the operation. 

In very deep cavities of this class, and especially when 
it is suspected that the pulp is near exposure, it is well to 
fill the deeper portion as far as the ledge cut around the 
margin with cement and allow this to harden before placing 
gold or amalgam. The best way to do this is to cut a 
bit of stiff paper or light cardboard to fit the cavity loosely, 



EXCAVATION OF CAVITIES BY CLASSES. 75 

and, having mixed the cement and worked it until it begins 
to stiffen, form a globule of suitable size and take this on 
the paper and place both in the cavity, the globule down. 
Then, with pressure upon the paper, the cement is properly 
packed into the cavity. When it becomes hard the paper 
may be pulled away. 

In second and third molars some differences of pro- 
cedure and of instrumentation are necessary on account 
of the differences of position. Often the bur can not be 
brought into position for effective use in squaring up the 
surrounding and pulpal walls, and this is done best w T ith 
the hoes 12-5-6 or 12-5-12, or, in some positions, hoe 
12-5-23, used with a scraping motion. In some cases the 
bur may be used effectively in the contra-angle hand- 
piece, but this is an awkward, and generally ineffective, 
instrument, and its use instead of hand instruments should 
be reserved for cases of the greatest necessity. 

The mesial wall, and especially the mesio-buccal angle 
of occlusal cavities in the second and third molars, should 
be so inclined to the mesial and buccal as to allow of 
packing gold against them easily. The amount of this 
inclination will depend upon the position and the character 
01 the approach to the cavity. If the mouth of the patient 
opens well, giving a good view, and allows instruments 
to be placed very nearly parallel with the long axis of the 
tooth operated upon, very little inclination to the mesial 
and buccal will be required. If, on the other hand, the 
mouth does not open well, and the approach of the instru- 
ments must be at a considerable inclination to the distal, 
the mesial wall and the mesio-buccal angle must be 
inclined in proportion, or sufficiently to allow of mallet 
force being applied parallel with the plane of this wall 
and angle. Any failure in this will require in filling with 
gold that the gold be packed aganst this wall with reverse 
pluggers or by lateral hand-pressure, which greatly 
increases the difficulty of making a good filling. When 
the preparation is for amalgam fillings this is not demanded, 
but it is still desirable. 

When the distal pit in the occlusal surface of the upper 
molars is the seat of operation, the procedure is not essen- 



/6 THE TECHNICAL PROCEDURES IX FILLING TEETH. 

tially different, except that the approach should be rather 
more from the buccal. The same instruments and the same 
methods should be employed. In these it is very generally 
necessary to cut out the disto-lingual groove to the crest 
of the lingual marginal ridge, and frequently to follow it 
over onto the lingual surface of the tooth. This should be 
done With the inverted cone bur. as previously described 
( pages 59 and 70 I . 

In the lower molars the grooves are generally deeper 
and more deeply sulcate than in the uppers, and will much 
oftener require cutting out to the crests of the marginal 
ridges. These teeth frequently have a lingual inclination, 
which renders occlusal cavities less easy of approach. In 
this they present great variation, many being as easy of 
approach as the upper teeth, and sometimes easier. Yet 
frequently there occurs a lingual inclination that renders 
them very difficult. The rule is that the lower molars are 
most accessible to instruments which approach them over 
the median line at the front teeth, and when much inclined 
lingually a line over the cuspid of the opposite side is often 
better. If these are prepared for filling with gold by the 
use of direct force, the mesial wall must be inclined to the 
mesial, and the mesial portion of the buccal wall must be 
strongly inclined to the buccal to allow of direct force 
being used. It is in these cases, however, that reverse 
pluggers have their greatest use, and when such cavities 
are to be prepared for the use of these, the mesial and 
buccal walls may be squared up in the axial plane* with- 
out inclination by use of the square-ended fissure bur in the 
contra-angle hand-piece, or with hoes 12-5-12 and 12-5-23, 
and the binangle chisels. Gold can then be well packed 
with reverse pluggers, but not by direct force. 

Occlusal cavities in the upper bicuspids are so easy and 
direct of access that little difficulty is experienced in their 
preparation. The principal points of instrumentation are 
the same as have been described. 

Occlusal cavities in the lower bicuspids are difficult only 
in cases of strong lingual and distal inclination of these 
teeth. In these cases the instrumentation is similar to that 

* Any plane, one direction of which is in the axial plane of the tooth. 



EXCAVATION OF CAVITIES BY CLASSES. 77 

described for the second and third lower molars, except 
that smaller cutting instruments will be required. 

Porcelain Inlays in Occlusal Surface. 

There does not seem to be much call for porcelain inlays 
in occlusal surfaces, yet there are some conditions in which 
they seem desirable. The rule is, that cavities in occlusal 
surfaces are easily and quickly filled with metal and that 
these fillings are very effective, whether of amalgam or of 
gold. Further, they are so much out of sight that in the 
esthetic sense there is no especial reason for using porce- 
lain. 

There seems to be a serious objection to the use of 
porcelain inlays in these surfaces for young people in 
whom there is still a strong tendency to caries, especially 
those who use their teeth vigorously, because of chipping 
of the margins and a reproduction of the conditions for the 
beginning of decay. 

In order to make inlays the margins of which will stand 
best, the cavo-surface angle of the margins of both the 
cavity wall and of the inlay must be right angles, never 
acute angles. This requires that in the preparation of the 
cavity the dentin and enamel walls be cut at right angles 
with the surface of the tooth, and that these shall not be 
beveled. This is a condition very difficult and often impos- 
sible to obtain upon the very irregular forms of the occlusal 
surfaces. If we bevel the cavo-surface angle, or leave it 
obtuse in cutting the cavity wall, it must be joined by an 
acute angle of porcelain. This acute angle of porcelain is 
very liable to break away under the stress of mastication, 
even if the inlay can be set without chipping it. When 
both are finished square, both are still liable to chip at any 
point where there is contact with an occluding tooth. 
First, the cement will wear away a little, then the angle 
of the enamel wall or porcelain wall, or both, will chip a 
little, thus exposing more cement, and so the process goes 
on until the conditions for the recurrence of decay are 
produced. 

In preparing occlusal surface cavities for porcelain 
inlays, the walls must be so cut that they will flare out just 



78 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

a little from the pulpal wall to the orifice of the cavity — 
just enough so that a matrix fitted to every part of the 
cavity walls will be easily withdrawn. The lines of the 
cavity outline should be so laid that the cavo-surface angle 
can be cut as nearly as possible at right angles with the sur- 
face of the tooth and also in such position that no part of 
this margin shall make contact with an occluding tooth. 
"When this cannot be done, the cusps of the occluding 
teeth should be ground sufficiently to relieve the contact. 

As porcelain in small masses is frail and very liable to 
breakage, the cavities should be as deep as the conditions 
will allow, in order to give more strength to the inlay. We 
should not simply follow deep grooves to a point that will 
make a good finish and fill these with little arms of filling 
material, as we may do with metal, for with porcelain these 
will break. We must, therefore, cut the occlusal surface 
boldly away to include such grooves. 

These facts naturally limit porcelain inlays in occlusal 
surfaces to cavities that are deep and broad. In this class 
of cavity, porcelain inlays may well be used in persons 
somewhat advanced in age who have become practically 
immune to the beginnings of decay, and especially for those 
whose peridental membranes have become weakened by 
disease, so that malleting for the condensation of gold could 
not well be borne. With our present experience with this 
material it would seem that its use in occlusal surfaces 
should be limited to this class of cases, and possibly some 
special conditions which call for esthetic effects. Gen- 
erally, however, when inlays are called for in occlusal sur- 
faces because of weakened membranes it is best to make 
them of gold. 

Pit cavities in the buccal surfaces of the molars must 
be distinguished sharply from smooth-surface cavities 
occurring in these surfaces. The pit cavities have their 
beginning only in the buccal pits and are primarily in the 
occlusal half of the buccal surface. Smooth-surface buccal 
cavities are primarily in the gingival half of the buccal 
surface and begin in the smooth portion of the enamel close 
to the gum margin. They are not always very close to the 



EXCAVATION OF CAVITIES BY CLASSES. 79 

gingival margin* of the buccal surface of the tooth, because 
the free margin of the gum often, particularly in young 
people, considerably overlaps the gingival portion of this 
surface. 

In these cavities the principles of instrumentation are 
the same throughout as that described for occlusal cavities, 
except as their location and the direction of approach ren- 
der differences necessary. Pits, in which decay has just 
begun, should be opened with burs as described for occlusal 
surfaces. Where more decay has occurred, so as to allow 
the use of chisels, or hoes used as chisels, the opening 
should be made by chipping away the enamel. The squar- 
ing up of the axial and surrounding walls and making the 
axial line angles definite should be done in the same way 
au in occlusal cavities, if done with burs, or if done with 
the hoes and chisels. Sometimes in the second molars and 
generally in the third molars the angle of approach will 
be such that the straight hand-piece of the engine can not 
approach the cavity at the correct angle, and the contra- 
angle hand-piece must be used, or, what is usually better, 
the work must be done with hoes and binangle chisels. 
In finishing the enamel walls the case is different, in that 
the enamel rods will generally be found perpendicular to 
the surface upon the central part, but inclining toward the 
occlusal as the occlusal margin of the surface is approached. 
Therefore the inclination of the enamel rods, or the direc- 
tion of the cleavage, should be closely noted while chip- 
ping away, and the occlusal enamel wall finished in inclina- 
tion to the occlusal, so as to be parallel .with the line of 
the cleavage. If in any case it is found that because of 
close approach to the occlusal surface, the inclination of 
the enamel wall to the occlusal will render the filling 
material too thin at its margin to have sufficient strength, 
the buccal groove should be opened over the crest of the 
marginal ridge and the filling carried onto the occlusal 
surface in the form of a step. Neglect of this precaution is 

* Note. — Distinguish carefully between the terms gum margin and gingival line, or 
a gingival margin of a surface of a tooth. Gum margin refers to the position of the free 
edge of the gum, while the gingival line is the line of junction of the enamel with the 
cementum, or the normal line of the attachment of the gums to the tooth. The gingival 
margin of a surface of a tooth is at its gingival line. 



80 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

causing the loss of many otherwise good fillings in this 
position. 

Pit or fissure cavities on lingual surfaces do not occur 
in the lower molars, but do occur occasionally as inde- 
pendent cavities in the lingual grooves of the upper molars 
and rarely in the mesio-lingual groove of the upper first 
molars, where there is a fifth cusp. The instrumentation 
in these is on the principles already given and requires 
no special description. 

In pit cavities in the lingual surfaces of the incisors, 
two points of special caution need to be mentioned. First, 
the location of the cavity is such that the pulp is easily 
reached, and accidentally and unnecessarily exposed, unless 
especial caution be observed. The use of burs should be 
limited strictly to the first opening of pits but little decayed. 
Neither inverted cone nor fissure burs should be used in 
squaring up the axial and surrounding walls, because the 
angle of approach is such that the sharp angle of the bur 
is presented toward the pulp, instead of its square end. 
This necessarily defeats the object as to squaring up the 
axial and surrounding walls, and rendering the axial line 
angles sharp, and especially endangers the pulp. All of 
this work should be done with the hoes and the smaller 
chisels. 

Except in the smaller cavities, the direction of the 
enamel rods will be much inclined to the incisal upon the 
incisal wall of the cavity. This should be carefully noted 
in clipping away the enamel, and the finished enamel wall 
should have the proper inclination to give it the necessary 
strength. 

Smooth-Surface Cavities. 

Classes 2. 3. 4 and 5 are all smooth-surface cavities. 
This distinction has been sufficiently described (page 8), 
but it is so important that it will be repeated here. The 
special points of distinction will also be further emphasized 
as the procedures are developed. 

Class 2. — Cavities in the gingival third — not pit cav- 
ities — of the labial, buccal or lingual surfaces of the teeth. 
— Of these the smooth-surface cavities in the lingual sur- 



EXCAVATION OF CAVITIES BY CLASSES. bl 

faces of the teeth are so infrequent that a mention of them 
seems to be all that is necessary. Difference in position 
calls for some differences in instrumentation between these 
and smooth-surface cavities on the labial and buccal sur- 
faces, but the principles of their preparation are the same. 

Labial cavities in the incisors and cuspids. — These cav- 
ities occur in surfaces of the enamel that are smooth and 
perfect. There is no pit, groove or fissure which serves as 
a starting point for the carious process. In this they are 
totally different in their conditions and surroundings from 
the cavities which begin in structural imperfections of the 
surfaces of the teeth, as pits and fissures. In the beginning 
of pit and fissure cavities, lodgments of debris and fer- 
mentable material are confined to the pit itself ; the surface 
of the tooth immediately surrounding the pit or fissure is so 
situated in relation to the uses of the teeth that it is con- 
stantly kept clean by the friction of mastication. Decay 
never begins upon clean surfaces. Therefore, there is no 
disposition for decay to spread upon the surface of the 
enamel, or to make a new. beginning in the immediate 
neighborhood of the pit or fissure; it spreads beneath the 
enamel only. 

In smooth-surface cavities the case is reversed. There 
is no pit or fissure that holds debris, but the position and 
relations of the surrounding parts of the surface to the 
first starting point of decay are such that it is not kept well 
cieaned by the friction of mastication and the motions of 
the tongue, lips and cheeks. Therefore, it is much of the 
time in an unclean condition. This area of uncleanness 
will vary indefinitely, so that the cases met with in prac- 
tice vary indefinitely. The first beginning of decay in these 
surfaces is central to the area of habitual uncleanness, or 
better, central to the greatest constancy of the uncleanness. 
As this is close to the gum margin, the first beginning of 
cavities in labial surfaces is usually close to the gum 
margin. But as the area of uncleanness is spread upon 
the surface, so has the beginning of decay a tendency to 
spread upon the surface. For this reason we find in labial 
and buccal cavities broad, shallow injuries to the enamel, 
very frequently, and many instances, when seen early, in 



82 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

which the enamel is broken through at a number of points 
near together, or spread in a line near the gum margin. 
An examination of these cases shows clearly the tendency 
for the decay to begin in the enamel in a constantly widen- 
ing area. Therefore, in preparing this class of cavities for 
filling, the principle is established of so extending the 
cavity outline as to include the area of the surface, which, 
under the conditions presented, is especially liable to decay 
in the future. This is called extension for prevention. It 
applies to all smooth-surface cavities. 

Case i. — A central incisor has shown sensitiveness near 
the gum margin, and upon passing a pointed exploring 
instrument over it, it catches at a number of points, and at 
some of these the point evidently passes through the 
enamel into the dentin. Examining the condition of the 
surface carefully, the appearance of an area of habitual 
uncleanness is found to extend along the gum line, occupy- 
ing the middle three-fifths of the surface mesio-distally, 
and about one-third of the surface gingivo-incisally. 

The incisor teeth are now well cleaned and the rubber 
dam adjusted over them, and the Hatch clamp applied to 
this tooth and the gingivals forced well out of the way. 
The surface indicated is well dried and examined. The 
enamel is found chalky, whitish, with openings through 
its thickness in the central area; and, extending mesially 
and distally in a crescentic form, there are whitish lines. 
In these lines an exploring instrument does not catch when 
passed lightly, but when a little force is used it does catch, 
showing a degree of softening of the enamel. Gingivally 
the line of injury ceases abruptly at the border of the 
gums. That portion of enamel covered by the gum is 
smooth and perfect. 

Procedure. — One, or two, or three vigorous strokes of 
chisel 15 breaks up and removes the injured and friable 
enamel over the central area, leaving the dentin bare, and 
reveals the fact that it is exceedingly sensitive. An inverted 
cone bur with sharp blades, in, millimeters in diameter, is 
placed with its end perpendicular to the labial surface 
directly into the central decay and quickly carried over 
the whole surface, extending the depth a little into the 



EXCAVATION OF CAVITIES BY CLASSES. 83 

dentin and somewhat enlarging the opening. The effect of 
this first movement is to remove the hypersensitive area 
almost, or quite, completely, and the rest of the excavation 
can proceed with much less pain. The same bur is again 
introduced and carried along the mark indicating the posi- 
tion of the gum line until the mesial border of the surface 
is nearly reached and all of the whitish line of the enamel 
removed. This may possibly have required two or three 
cuts, but often may be done with one. With the same bur 
the distal part is cut out the same way and to the same 
extent. The result is a narrow, crescent-shaped cavity, 
no wider than the bur, following the gum line from an^e 
to angle (nearly — not passing around quite to the actual 
line of the mesial or distal angle of the tooth, though in 
many cases it should). 

The incisal wall of this is now broken down with the 
straight chisel, and if still further extension to the incisal 
seems required, the bur is passed around the incisal wall, 
cutting away the dentin from beneath the enamel, which 
is again chipped away with the chisel. This cutting should 
be carried to the incisal until such portion of the surface as 
may seem especially liable to future decay has been 
removed. Generally, it is not necessary to make consider- 
able extension in this direction. 

Next, attention is turned to the gingival wall. The first 
cut has removed all injured enamel in this direction, but 
the length of the free gum margin will allow of the cavity 
being extended more, without reaching the gingival line, 
and a finish can be made against perfect enamel that will 
be fully covered by the gum margin. This is just such a wall 
as is most desirable in all smooth-surface labial or buccal 
cavities. Decay never begins under a covering of healthy 
gum, and as long as the margin of the filling is thus pro- 
tected, and the margin well made, it is safe ; therefore the 
enamel is carefully planed away to the proper position 
with very sharp chisels with a motion along the length 
of the wall or from mesial to distal, and from distal to 
mesial. In executing this the thumb and palm grasp is to 
be preferred. 

The dentin wall is now cut back with the same inverted 



84 THE TECHNICAL PROCEDURES IX FILLING TEETH. 

cone bur used previousl)', or with hoe 6-2-12 or 8-3-12, and 
slightly undercut in order that it may be retentive. Any 
corrections required in the gingival enamel wall are now 
made. This should be inclined strongly to the gingival, 
the particular inclination having been determined by ob- 
servation of the direction of the enamel rods while trim- 
ming away the enamel from this surface. The incisal wall 
is also squared up and the dentin wall slightly undercut — 
about as an inverted cone bur placed with its flat end on 
the axial wall would do it. This is generally easier done, 
however, with hatchet 6-2-23. Then the enamel wall is 
finished, inclining it slightly to the incisal. Its cavo-surface 
angle should be slightly beveled by a planing motion with 
a very sharp chisel, carried very lightly along its length. 
The mesial and distal angles of the cavity are similarly 
finished. Before filling, the operator may, if he thinks it 
will be more convenient for starting the filling, cut two 
convenience points, one in the axio-mesio-gingival angle 
and one in the axio-disto-gingival angle. This should be 
done with the square end of an inverted cone bur, about 
r 6 o or *6 millimeters in diameter, and be about half the 
depth of the head of the bur. After forcing the bur into 
the dentin to this depth it should be drawn a little away 
along the axio-gingival line angle, extending the pit into a 
slight groove that diminishes and runs out at a length of 
about three diameters of the bur. This little extension 
will increase the hold of the gold and render the starting 
easier and more certain. 

"We now have a crescent-shaped cavity, with somewhat 
blunt points, with a perfectly flat axial wall that includes 
the area of the surface most liable to decay, prepared for 
filling with 

Preparation for Porcelain Inlay. 

This particular class of cavities, on account of the gold 
filling being fully exposed to view, is one that is especially 
suitable for porcelain inlay work, and for esthetic results 
the inlay is very desirable. 

For the reception of the inlay the preparation of the 
cavity should be different in several important particulars. 



EXCAVATION OF CAVITIES BY CLASSES. »5 

Instead of being as shallow as the penetration of decay 
will permit, it should be cut as deep as safety to the pulp 
will allow, so as to give as much body of porcelain as 
practicable to give greater strength. All of the extensions 
should be the same as when gold is to be used, or, if any 
difference, greater, and the general outline should be the 
same. But there should be no undercuts in any part of the 
cavity, nor should the angles with the axial wall be so 
exactly squared out. It is better that these angles be left 
somewhat rounded, as would be done with a round bur 
about one millimeter in diameter, or with a 12-5-12 or 
12-5-23 hoe, the cutting edge of which is rounded like that 
ot a spoon. From this the walls should be finished per- 
pendicular to the surface of the tooth at all points. So 
finished, the incisal and gingival walls will be very nearly 
parallel, but not quite, or in such form that they will flare 
out just a little toward the orifice of the cavity. This 
should be just enough so that a matrix burnished perfectly 
to the walls of the cavity in every part will be easily 
withdrawn. Generally there should be no beveling of the 
enamel margins, for it usually happens in the cavities of 
this class the direction of the enamel rods where the mar- 
gins are laid are very nearly perpendicular to the surface 
of the tooth, except at the gingival, where there is the 
least danger of chipping-. When this is found, with the 
rods inclining much to the gingival, it will be best to make 
something of a bevel of the cavo-surface angle to 
strengthen it and sharpen the margin of the inlay to meet 
it. Also, in any case in which the inlay may extend much 
to the incisal, a moderate inclination of the enamel wall 
toward the incisal will be safer than to cut this perpen- 
dicular with the surface of the tooth. In placing an inlay 
we do not incur the same liability to fracture frail enamel 
margins as in malleting gold over them, but to leave un- 
supported short ends of enamel rods on the margins is to 
invite chipping with the least solution of the cement. The 
general rule should be to cut the enamel wall in the line 
of the enamel rods without bevel of the cavo-surface angle 
and to take great care to so lay the cavity margin that this 
preparation will give the least bevel practicable. We can- 



86 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

not make a very acute edge of porcelain that will not be 
liable to chip and become rough, if indeed we can set it in 
the cavity without chipping. It should be made as nearly 
a right angle as possible. 

Case 2. Left upper central incisor with labial decay. — 
Cavity open and occupying the gingival third of the sur- 
face inciso-gingivally, and the middle three-fifths mesio- 
distally. The incisors are cleaned, the rubber dam adjusted, 
the gingivus pushed well back with the Hatch clamp, and 
the tooth dried. It is now seen that a line of injury to 
the enamel runs from the mesio-gingival angle of the cavity 
to a rilling in the mesial surface, and another such line con- 
nects with the distal surface, in which there is a small 
open cavity. The filling in the mesial surface is good and 
sufficient, except at its labio-gingival angle, where slight 
decay has begun. These lines of injury show as a whiten- 
ing of the enamel only, there being as yet no apparent 
loss of substance. The patient is twenty years old and 
suffering badly from caries. 

Procedure. — All overhanging enamel is chipped away 
from the incisal portion with chisel 20, using the thumb 
and palm grasp, and the dentin wall squared up to a suffi- 
cient depth. Then with chisel 15 the gingival wall is cut 
away to sound dentin, again using the thumb and palm 
grasp and cutting from mesial to distal. This wall is found 
solid and clean very close to the gingival line, only a very 
slight band of thin enamel remaining, but it is sufficient 
to prevent actual injury to the attachment of the peridental 
membrane. This is favorable and regarded as important, 
because it insures a healthy free margin of gum after the 
operation. The angles are also cut to sound dentin with 
the chisel. At the angles the superficial injury to the 
enamel is found to be more extended than the decay in 
the dentin. An inverted cone bur, 1 millimeter in diam- 
eter, is placed in the mesio-gingival angle of the cavity 
with its square end toward the axial wall, and entered into 
the dentin just beneath the dento-enamel junction and 
carried along the line of whitened enamel to the point of 
connection with the filling in the mesial surface. The 
enamel is chipped from the incisal wall of this cut with 



EXCAVATION OF CAVITIES BY CLASSES. 87 

chisel 15, and the cut widened by again passing the bur, 
cutting the dentin toward the incisal. This portion of 
the incisal wall is now trimmed smoothly to its connection 
with the incisal wall of the original cavity. The same bur 
is now entered in a similar manner into the disto-gingival 
angle of the cavity and carried to the distal along the line 
of the whitened enamel to the margin of the labial surface 
and slightly over onto the distal surface, but not connected 
with the distal cavity. This cut is stopped at a point 
upon the distal surface at which the outline of the distal 
cavity, when prepared, will cut into it. This cut is now 
widened toward the incisal by chipping the enamel with 
the chisel and again cutting away the dentin with the bur 
and smoothly connected with the incisal wall of the origi- 
nal cavity. This completes the outline of the cavity. The 
surrounding walls are clean and the retention form par- 
tially provided for, but the carious material in the central 
and deeper portions of the cavity is undisturbed. It is still 
a question whether or not the pulp will be found exposed 
when this is removed. The right-hand spoon, 20-9-12, used 
with the palm and thumb grasp, is now entered under the 
distal margin of the carious mass and its edge swept across 
to the mesial, along the incisal wall, cutting out the de- 
cayed material. Another similar cut is made, directed to 
the gingival half of the cavity, by which the last of the 
carious material is removed, leaving all parts of the cavity 
clear and white. The pulp is found covered by sound, hard 
dentin. The edge of the spoon is now passed carefully 
over the surface of the cavity with a scraping motion, to 
be sure that no softened material remains. This central 
portion being deeper than is desirable to make the sur- 
rounding walls, it may be filled for a part of its depth 
with zinc oxyphosphate as a protection to the pulp, or 
better, its central portion may be covered with a bit of 
quill after the anchorage of the filling has been started 
and the gold built upon and over it. The anchorage is 
now to be perfected. The gingival dentin wall, which was 
left inclined to the gingival by the chisel, is squared up 
with hoe 12-5- 12 and slightly undercut with hoe 8-3-12 or 
6-2-12. Then the enamel wall is finished to the mesial 



88 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

and distal angles with chisel 15, and the cavo-snrface angle 
very slightly beveled. A convenience pit is now made, 
one toward the mesial and one toward the distal in the 
gmgivo-axial line angle with an ie millimeter inverted 
cone bur. and each extended slightly by grooving toward 
the central part of the length of this line angle. The 
incisal dentin wall is slightly undercut with an inverted 
cone bur held with its square end to the axial wall and 
passed along from mesial to distal, or, better, with hatchet 
8-3-23 or 6-2-23. The incisal enamel wall is finished, being 
inclined slightly to the incisal and its cavo-surface angle 
very lightly beA'eled,, the straight chisel 20 being used, and 
cutting in the direction of the length of the wall, using 
the thumb and palm grasp. 

This cavity as prepared involves nearly half the labial 
surface inciso-gingivally, and the whole surface mesio- 
distally, the filling in the mesial cavity making a portion 
of the wall. Upon the distal the filling, after being made, 
will be cut into when the cavity on the distal surface is 
prepared. It is a somewhat extreme type of labial cavity. 

In preparing this cavity for a porcelain inlay, but little 
difference would be made in its general form. A capping 
over the nearly exposed pulp would not be regarded as 
necessary because of the poor conducting qualities of the 
porcelain. The extension would be carried a little more 
boldly around the angles of the tooth, both mesially and 
di stally. Xo undercuts would be made. The dentin and 
enamel walls would be finished at right angles to the sur- 
face of the tooth, except that at some points where the 
inclination of the enamel rods requires some inclination of 
the enamel wall. In the last cutting in the extension a 
round bur, one to one and a half millimeters in diameter, 
or the hoe with rounded edge, might be used instead of 
the inverted cone bur, thus rounding the angles with the 
axial wall, and the incisal and gingival walls finished up 
from that. The gold filling in the mesial surface would 
be used as one Avail of the cavity, the same as with the 
gold filling, but should be cut so far around the angle of 
the tooth that the porcelain would hide the gold. The 
cavitv in the distal surface should be excavated and filled 



EXCAVATION OF CAVITIES BY CLASSES. 89 

with gold preparatory to making the inlay. It should be 
finished in such form that its labial margin would be cov- 
ered by the inlay, which should be extended sufficiently 
around the angle of the tooth to effectually hide the gold. 

In any of the incisors or cuspids, labial cavities may be 
treated in a similar manner as illustrated in the two pre- 
ceding cavities, when it seems desirable to use porcelain 
inlays for the better esthetic effects. Buccal cavities in the 
bicuspids may be similarly treated. 

Labial cavities in the upper laterals and cuspids, in the 
lower front teeth, buccal cavities in the bicuspids and in 
the first molars, would be excavated in the same manner 
and with the same instruments. The thumb and palm 
grasp of instruments cannot so frequently be used to ad- 
vantage in buccal cavities in bicuspids and first molars as 
in like positions in the anterior teeth. In the second and 
third molars this grasp is usually inapplicable. 

Generally the inverted cone or square-ended fissure bur 
may be used with its shaft at right angles to the buccal 
surfaces as far back as the first molar, and in occasional 
favorable cases in the second molar. Usually the contra- 
angle hand-piece must be used if the bur is emplo}^ed in 
excavating buccal cavities in the second or third molars. 
In most cases, however, the instrumentation is easier, and 
the excavation is made quicker by using chisels and the 
hoe excavators. These may be effectually assisted by using 
the inverted cone bur for making extensions toward the 
mesial, chipping the enamel from the occlusal wall of the 
slot cut, and again undermining with the bur. 

The difficult point in the preparation of buccal cavities 
in the second and third molars occurs when considerable 
extension of the cavity to the distal is required. If the 
dentin is hard and firm, and the enamel still strong, it is 
difficult to cut with hand instruments. This work is 
effectively done by placing an inverted cone bur, to milli- 
meter in diameter, used in the contra-angle hand-piece, in 
the distal portion of the cavity, and entering it in the dentin 
near the dento-enamel junction, and pushing it to the distal, 
and at the same time drawing it to the surface. By repeat- 
ing this motion in cut after cut, the required extension may 



90 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

be made. This slot is now extended by chipping the 
enamel, and again undermining with the burr, as described 
for other positions. This plan of operating is not always 
available, however. Often the clamp must be used on 
the second molars, always on third molars, and the bow 
of the clamp is in the way of the contra-angle hand-piece. 
In this case, if burs are used at all, they must be used by a 
different method. An i 8 o millimeter inverted cone bur, 
used in the straight hand-piece, is placed with its end 
against the distal wall of the cavity, and its square end 
entered in the dentin at the dento-enamel junction. Now, 
by swaying the hand-piece back and forth, the bur is caused 
to enter the dentin to about the depth of its head ; then, by 
pressure toward the surface, while withdrawing the bur, 
it is made to cut the enamel from its inner surface. By 
repeating this motion, the enamel may be cut through and 
a slot formed of any desired extension. The enamel may 
now readily be pared from the margins of this with straight 
chisels, the enamel further undermined to the occlusal or 
to the gingival by cutting out dentin along the dento- 
enamel junction with the bur, and removing more enamel 
with the chisel. In this use of instruments the axio-gingi- 
val and axio-buccal line angles, as made with the bur, are 
rounded and not in good condition to receive filling ma- 
terial. This is remedied by cutting these to sharp and 
definite angles with hoe 6-2-12 or 6-2-23, by a scraping 
motion. When the cavity is broad gingivo-occlusally, the 
size 8-3 of the hoes may be used. 

Buccal cavities often extend so far gingivally that the 
gingival wall is beyond the gingival line and the cavo- 
surface angle is of cementum instead of enamel. This must 
always be regarded as unfortunate, for the reason that the 
attachment of the gum to the tooth has been injured and 
because of the increased difficulty of making the filling. 
The injury to the attachment of the gums is necessarily 
permanent, and yet, if the operation is well and smoothly 
made, a fair degree of health of the gum margin is gener- 
ally maintained. In these cases it is best to remove the 
attached membrane from the cementum sufficiently to allow 
room for the clamp and provide additional room to readily 



EXCAVATION OF CAVITIES BY CLASSES. 9 1 

see the cavity margin after the filling is in place, in order 
that the filling may be finished definitely and smoothly to 
the tooth surface. It is better to destroy the attachment 
a little further and secure a smooth, perfect finish than to 
risk imperfect work at so important a point. 

Class 3. — Cavities in the proximate surfaces of the in- 
cisors and cuspids, which do not involve the removal and 
restoration of the mesial or distal angle. — In the excava- 
tion of this class of cavities a much greater range of* forms 
of cutting instruments may be used effectively than in 
other classes, and a greater variation of method of instru- 
mentation is consistent with rapid and thorough operating. 
In the work the ordinaries are used 'almost exclusively, the 
bur being employed only to accomplish a few special pur- 
poses. The cavities are all smooth-surface cavities and the 
rules of extension for prevention are applied in their 
preparation. 

The preparation for gold filling will be presented first 
and afterward the preparation for porcelain inlays, which 
in this case will be markedly different in form. 

Case 1. — The left upper central incisor has a decay in 
its mesial surface, just to the gingival of its contact point. 
Apparently it is small, but a curved exploring instrument, 
introduced from the labial or from the lingual, enters 
through the enamel. 

Procedure in preparation for gold fillings. — The first 
procedure is to free all of the incisor teeth of debris or 
micro-organisms and gummy material, particularly about 
their gingival portion, and apply the rubber dam. Dry 
the teeth and apply the Perry separator and get sufficient 
separation to pass a thin polishing tape between the teeth. 
Then, with the 8-3-6 hoe used as a chisel, begin near the 
labial margin of the cavity to break down the overhang- 
ing enamel, chipping from the surface into the cavity. 
This should generally be done by hand pressure, being- 
careful to place the edge of the cutting instrument very 
near the margin in each instance and split off the enamel 
in little flakes. In this cutting the third finger should be 
very securely rested upon the adjacent teeth and the mo- 
tions of the instrument so closely controlled that its edge 



92 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

will not be thrust into the depths of the cavity and cause 
pain. Continue this cutting until the enamel is found sup- 
ported by sound dentin, or until the cavity of decay is well 
exposed. In many cases it will be best in this position, 
when decay is extensive, to leave some enamel unsupported 
by dentin, especially when of about full strength, rather 
than expose so much filling material as the complete re- 
moval of the enamel would do. When this wall has been 
chipped away sufficiently, chip away the lingual wall in 
the same way and with the same instrument, working from 
the lingual. This, if the cavity be not very small, will give 
good access to all of its parts. If the cavity is small, take 
hatchet 8-3-12 and introduce its blade between the teeth 
from the labial, with the edge directed to the gingival, 
catch the enamel near the cavity margin and chip it away 
by a prying motion, using the proximating tooth as a ful- 
crum, removing as much enamel in this way as practicable. 
Only the thinner portions of weakened enamel margins can 
be removed by this motion ; but now a stronger instrument 
may be used, sufficient room having been obtained for its 
introduction. Generally, hatchet 12-5-6 or chisel 10 may be 
introduced against the labial enamel wall, with its edge 
directed toward the gingival and the enamel wall trimmed 
away, using strong hand pressure, and, by changing the 
direction, the cutting can be continued along the gingival 
wall to or past the labio-lingual center of the tooth. With 
the same instruments working from the lingual, the lin- 
gual wall is next cut down in the same way. to. and some- 
what past, the linguo-gingival angle of the cavity. For 
trimming the remainder of the gingival wall hoe 12-5- 
will be required, or the 8-3-6 if the cavity is not opened 
sufficiently to admit the larger instrument. This is done 
with a scraping motion. Frequently hatchet 12-5-12 will 
do this well, working from the labial. The gingival wall 
should be cut to sound dentin and made as nearly flat in 
the horizontal plane as practicable. 

Xow. examine carefully as to the requirements of ex- 
tension for prevention. In most cases a line of superficial 
injury to the enamel will be found running away labially 
from the labio-gingival angle of the cavity near the gum 



EXCAVATION OF CAVITIES BY CLASSES. 93 

line. Another line of superficial injury leads away in sim- 
ilar fashion from the linguo-gingival angle. Often, also, 
particularly in the smaller cavities, there is superficial 
enamel injury to the gingival of the gingival wall. The 
cavity must now be extended so that it will include all of 
these superficial injuries. To do this, place a small inverted 
cone bur ( A or A- millimeter) in the labio-gingival angle, 
introducing it from the lingual in most cavities, and enter 
the dentin close to the enamel junction, and swaying the 
hand-piece as much as the position will aljow, undermine 
the enamel in the direction of the line of superficial injury, 
sinking it at first about the depth of the bur head. Then 
very slowly withdraw the bur, pressing it toward the labial 
and incisal, thus widening the cut in this direction. Now, 
with the hoe 12-5-6 or 8-3-6, the undermined enamel may 
be chipped away. These cuttings may be repeated until 
the extension in this particular direction seems sufficient. 
If now it is desirable to extend the cavity to the gingival, 
the same bur may be introduced as before, and drawn 
toward the lingual with pressure against the gingival wall, 
cutting the dentin close against the dento-enamel junction, 
and the undermined enamel chipped away with the hoes 
or hatchets, working from the labial. In many cases all 
of this cutting with the bur can better be done from the 
labial, keeping the shaft of the instrument as nearly as 
possible in line with the central axis of the tooth. After 
some cutting in this way, the attention should be turned 
to the linguo-gingival angle. To extend this the same bur 
should be introduced from the labial and its end entered 
into the dentin at the dento-enamel junction in the direc- 
tion to undermine the line of injured enamel. In this 
position the first cut should generally be made as near to 
the lingual enamel plate as is desirable to cut the cavity, 
and the bur should be drawn back with pressure toward the 
gingival, extending the undermining in that direction. It 
is also generally desirable in this position to again intro- 
duce the bur, and while drawing it toward the labial make 
pressure against the undermined enamel, so as to weaken 
it. Then it may be broken away with hoe 8-3-12, catching 
the edge of the instrument on the surface and using a pull- 



94 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

ing motion, throwing the chips into the cavity, or it may 
be cut away by using a scraping motion from labial to 
lingual with hoe 12-5-12, or 8-3-12 if the first is too broad 
to enter the' cavity well. Also this is well done with 
hatchets 12-5-12, or 8-3-12, or enamel hatchet 10-6-12 work- 
ing from the labial. If still more extension to the gingival 
is required, it is readily done by passing the square end 
of the bur along the gingival wall, cutting out the dentin 
close against the dento-enamel junction and afterward re- 
moving the enamel. In excavating and extending cavities 
in the proximate surfaces of the incisors and cuspids, it 
should be noted particularly that these surfaces are wedge- 
shaped or triangular, with the base of the triangle at the 
gingival margin, and that the finished cavity should have 
that form, with its labio-gingival and linguo-gingival angles 
widely extended toward the angles of the surface decayed. 
The gingival wall should be perfectly flat mesio-distally, 
with the axio-gingival line angle sharp. Labio-lingually 
it should be either straight and parallel with the horizontal 
plane of the tooth or curved with its convexity to the 
incisal. 

The incisal angle should next receive attention. It 
often happens that decay has extended along the dento- 
enamel junction considerably in this direction. The enamel 
should be chipped away with hoe 12-5-12 or 8-3-12 until 
sound dentin has been fully reached, and in doing this 
very careful attention should be given to the direction of 
cleavage with reference to the final inclination of the fin- 
ished enamel wall. When the outline form has been at- 
tained the incisal angle should be undercut for retention. 
Usually this should be done before looking specially to 
the retention in other parts of the cavity, for the strength 
required of these will depend much upon the strength of 
the incisal retention. The incisal retention is made by 
undercutting to the incisal in the form of a groove. The 
incisal angle is first well rounded and the dentin cut away 
to some depth from the dento-enamel junction directly at 
right angles to the axial surface of the tooth, with hoes 
8-3-12 and 8-3-23, or equivalent hatchets, using angle 23 
mostly close against the labial wall. Then hatchet 5-3-28 



EXCAVATION OF CAVITIES BY CLASSES. 95 

or if that blade is too long, 3-2-28, is used for 
cutting a groove in the incisal angle, and extending it 
along the labio-axial line angle. The instrument is 
introduced from the labial, its edge directed to the 
incisal, and, beginning at the labio-axial line angle a little 
removed from the incisal angle, carry its edge toward the 
incisal and lingual around the angle, in part by a twist 
of the instrument. Then it is placed well to the lingual 
and swept in the opposite direction, or toward the labial, 
all the time cutting close against or slightly into the axial 
wall. These motions are repeated until the groove is of 
sufficient depth. Now, with the 8-3-23 hoe, or if the cavity 
is small the 6-2-23 hoe, introduced from the labial and with 
its edge turned to the labial or the axial wall, the axio- 
labial line angle is made sharp and definite along the length 
of it well to the gingival, using a scraping motion from 
the gingival toward the incisal. Often the 6-2-23 hatchet 
will do this as well, using it with a back-and-forth scraping 
motion, holding the shaft of the instrument at right angles 
to the long axis of the tooth. The axio-lingual line angle 
is now made definite throughout its length, using hoes 
8-3-12 or 6-2-12 or the 6-2-23 near the incisal angle. This 
should be completed to, and into, the axio-linguo-gingival 
ar.gle. Undercutting at the axio-linguo-gingival angle for 
retention will depend upon the strength of the incisal an- 
chorage ; if this be good, but slight retentive form, just suffi- 
cient to serve in starting the filling, is all that is needed 
in this position. The axio-labio-gingival angle, whch 
has been left sufficiently definite by the bur, is now slightly 
grooved for a short distance toward the incisal, completing 
the retentive form by squaring out with hoe 6-2-12 or 
hatchet 6-2-23. Any decay now remaining in the deeper 
parts of the central portion of the cavity is removed with 
spoons 10-6-12. Or if the cavity is large, the spoons 1 5-8-12 
may sometimes be better. The cavity is now ready for the 
finish of the enamel walls and the cavo-surface angles. 

The enamel wall is planed smooth in every part and 
its inclination corrected. If the operator has noted care- 
fully the direction of the cleavage of the enamel at all 
points while chipping it away, he will be at no loss as to 



g6 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

the correct inclination at the different points, he remember- 
ing' that this shall follow closely the cleavage lines. 

This is done in all. parts with the chisels, except some 
portions of the gingival enamel wall and a short reach upon 
the lingual wall where it joins the incisal angle. The 
movement of the chisel should be along the length of the 
enamel wall, cutting very lightly. It must be very sharp 
to be effective. At the labio-gingival and linguo-gingival 
angles the outline should form short curves, no matter how 
sharp the angles of the dentin walls; sometimes it is diffi- 
cult to plane the whole length of the gingival wall smoothly 
with the chisel, especially where it joins the curve at the 
linguo-gingival angle. Here hatchet 12-5-6 or 12-5-12 an- 
swers better; or occasionally one of the hoes. These instru- 
ments will also smooth the lingual portion of the curve 
at the incisal angle in many cases. At the incisal angle, the 
inclination of the enamel wall must generally be strongly 
toward the incisal, especially in distal cavities, in order 
to follow the length of the enamel rods. 

When the trimming is done, note carefully whether the 
retentive form has been injured at any important point by 
trimming too deeply, and make such corrections as may be 
required. 

Finally, bevel the cavo-surface angle in all parts of the 
enamel margin, using the chisel for nearly all this work. 
At a few points, especially along the gingival, the hatchet 
12-5-6 or 12-5-12, or the 10-6-12 enamel hatchet, will do 
the work easier. Make the toilet of the cavity and fill. 

General observations on the preparation of proximate 
cavities and the incisors and cuspids. — In all cases the 
enamel margins should be cut sufficiently around the curves 
of the surface toward the labial and lingual, that the mar- 
gin will be well away from the contact of the two teeth 
when the filling has been finished. At the gingival the 
margin should be well covered by the gum septum when 
this is in its normal position. The gum septum should be 
carefully preserved from injury in all parts of the operation, 
for upon the health of this tissue depends largely the health 
and good appearance of the tooth. Toward the incisal the 
cutting should always include the normal contact point in 



EXCAVATION OF CAVITIES BY CLASSES. 97 

distal cavities. In mesial surfaces the contact point is 
sometimes so near the incisal angle that this is impracti- 
cable. In these cases, unless strictly required by the ex- 
tension of decay, the original contact point of the enamel 
should not be removed, but a new contact should be made 
by a slight fulness of the filling a little to the gingival of 
the position of the original contact, so that the incisal 
enamel margin will be held a little apart from contact with 
the proximating tooth. A very little space at this point is 
sufficient, for the reason that to the incisal of the contact, 
in the use of the teeth, the excursions of food constantly 
clean the margin of the filling. 

In medium and large cavities it is best to cut the labial 
wall well over onto the labial surface of the tooth, for the 
reason that, if cut only to the mesio-labial or disto-labial 
angle the light will not reflect from the surface of the filling 
to the observer, and it will appear as a dark cavity. A little 
further extension to the labial relieves this and gives the 
appearance of a filling. A little careful observation of this 
point will prevent mistakes that are often very annoying 
to sensitive patients. The appearance of sharp angles in 
cavity outlines that are exposed to view should be avoided. 
Slightly curved lines are better than straight lines. But 
the key to good appearance of operations on the incisors 
is perfect tooth form, including particularly the full mesio- 
distal breadth of the tooth. In the incisors, and especially 
in the laterals, the labial embrasure is usually well rounded 
out, and open, because of the rounded form of the labio- 
mesial and labio-distal angles of these teeth. Upon the 
lingual the embrasures are very shallow and close, because 
of the acuteness of the mesio-lingual and disto-lingual an- 
gles of the teeth, and the flatness of the lingual surfaces 
from mesial to distal. For this reason the proximate cavi- 
ties in these teeth often begin well toward the lingual and 
burrow much more under the enamel of the linguo-mesial 
or lingual-distal angles of the tooth than toward the labial. 
The result is that the enamel to the lingual is often under- 
mined and very thin from injury of the inner half of its 
thickness from backward decay, or decay of its inner sur- 
face. Also the lingual marginal ridges are often quite 



98 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

sharp and the course of the enamel rods uncertain, so that 
a good margin cannot certainly be made upon the sharp 
curves of these ridges. Therefore, when the enamel mar- 
gin of the cavity must be laid against the enamel of the 
lingual marginal ridge, it is best to cut away the marginal 
ridge and lay the enamel margin of the cavity on the lin- 
gual surface of the tooth. In this case this enamel wall will 
be cut parallel with the axial wall of the cavity, or in the 
labio-lingual plane of the tooth. Frequently this enamel 
wall will be level with the axial wall of the cavity, and this 
renders the placing of the filling more than ordinarily 
difficult. When the amount of tissue will allow, it is well 
to sink the lingual portion of the axial dentin wall suffi- 
ciently to obtain a slight ledge at the lingual. This is 
readily done with a few strokes of the 6-2-12 hoe for the 
gingival third, and with the 6-2-23 hoe for the incisal two- 
thirds of the lingual wall, introducing these instruments 
from the labial. 

Procedure in preparation for porcelain inlay. — In this 
case the preparation for placing the rubber dam will be 
the same as for gold filling. Generally the separation for 
gaining space between the teeth will be the same, and 
about the same amount of room will be required. But there 
will be many cases occurring where the cavities are large 
and extend far to the gingival in which the claws of the 
separator will be in the way of the margins of the matrix 
that must be fitted to the walls of the cavity and also to 
all parts of the surface of the tooth about its borders. In 
such cases the Perry separator should be placed and a part 
of the preparation of the cavity made at the first sitting. 
The space gained by the separator should be as great as is 
consistent with safety to the membranes of the teeth. 
Then the cavity formed should be filled temporarily with 
gutta-percha, extending firmly against the proximating 
tooth in such form as to maintain, after the removal of the 
separator, the full separation that has been gained. This 
should remain in place several days, when at the next sit- 
ting the gutta-percha may be removed and the teeth will 
remain apart without the separator long enough to com- 
plete the operation. In a few cases it may be required 



EXCAVATION OF CAVITIES BY CLASSES. 99 

that this be done the second time to gain sufficient space. 

This separation may also be obtained by the older 
methods of separation with rubber wedges or other means 
of slow wedging, but this causes so much more soreness 
of the teeth, and withal, so much more pain and trouble 
to the patient that the more convenient separator should 
generally be employed. 

The first thing to be considered in the preparation of 
proximal cavities in the front teeth for porcelain inlays is 
the fact that the inlay must be inserted in one piece, and 
as the teeth cannot be separated sufficiently for the inlay 
to be inserted in the direction of the orifice of the cavity 
as prepared for gold filling, the cavity must be so cut that 
it may be inserted from either the labial or the lingual. 
This requires that one of these walls be cut away to, or 
almost to, a level labio-lingually with the axial wall, less 
the room the opening of the embrasures between the teeth 
will give for slipping the inlay in at an angle, which will 
be of value in a certain proportion of cases. Therefore, in 
each case a choice must first be made as to which of these 
walls must be removed. Generally this will depend upon 
the direction and extent of the decayed area. If the decay 
has burrowed mostly to the labial, leaving a large portion 
of the labial enamel plate unsupported and much weak- 
ened, this wall should be removed boldly to a level with 
the axial wall, or to such an extent that the opening of 
the labial embrasure will allow the inlay to slip into place. 
As much of the lingual wall should be retained as is con- 
sistent with good strength and a sufficient extension to 
make the case good against recurrence of decay. If the 
lingual wall is decayed most and much the weaker, this 
wall should be removed and the preparation made for the 
insertion of the inlay from the lingual, retaining as much 
of the labial wall as is consistent with proper strength. 
At this point I should warn the student that a porcelain 
mlay must not be cemented against unsupported enamel 
in any position exposed to view, because the cement is 
opaque, and this opacity, showing through the transparent 
enamel on the labial side, will destroy the harmony of color 
that we depend upon for a good esthetic effect. In either 

LtfC. 



IOO THE TECHNICAL PROCEDURES IN FILLING TEETH. 

case the gingival dentin wall and the incisal dentin wall 
should be cut about parallel with each other, though a 
very slight undercut of the incisal wall may give better 
retention when the handling of the matrix, described later, 
can be managed. If the inlay is to be inserted from the 
labial, the gingival and the incisal walls should be so cut 
that they will open in the labial direction just enough so 
that in pushing the inlay into place it will tend to close 
upon the cement between it and both of these walls in such 
a way as to secure the perfect, cementing of these joints. 
In these cavities the greatest difficulty is found in adapting 
the platinum matrix to the walls of the cavity and to the 
surface of the tooth about the cavity margins and to have 
space in which this may be removed from the cavity with- 
out danger of so bending it as to change its form. This 
will often require more separation than that required for 
the insertion of the inlay, and will occasionally call for 
excessive separation or excessive cutting in the opening of 
the cavity. The rule should be that the matrix, after being- 
loosened from the cavity walls, should readily slip out to 
the labial, or to the lingual, and that the overlaps upon 
the surface of the tooth that interfere with this movement 
should be cut as short as practicable. 

For convenience in all parts of this operation the labial 
opening of the cavity is much the preferable one, and should 
be chosen whenever the final results can be made as good. 
The manipulation in this preparation becomes especially 
easy when the work is done from the labial on account of 
the broad and direct approach to all parts of the cavity. 
Very much of the work of preparation may be conveniently 
done with chisels and burs. This must be so managed that 
the cavo-surface angle of the cavity shall be a right angle 
in all of its parts, or as near an approach to this as the 
direction of the enamel rods will allow and at the same 
time subserve other requirements. 

It should always be made a special object to so cut the 
cavity wall that its marginal edge shall be presented 
directly toward the observer at the most important posi- 
tion of observation, for in this position the cement shows 
ieast. If it is not so placed, the seam of the opaque cement 



EXCAVATION OF CAVITIES BY CLASSES, IOI 

will shoAV through either the porcelain or the tooth tissue, 
both of which are translucent, and destroy that harmony 
of color that goes to make up a good esthetic effect. 

The cavity wall forming this angle should be trimmed 
perfectly smooth with keen-edged chisels, used with a very 
light planing motion as nearly parallel with the length of 
the margin as possible, being careful that the angle is per- 
fectly sharp. Often, especially in the incisal portion of the 
cavity, this enamel margin, if finished at right angles with 
the tooth's surface, will .be exceedingly frail and easily 
chipped, and requires the most delicate handling, both in 
its final preparation and in the fitting of the matrix. In 
this case it is better to incline it in the direction of the 
length of the enamel rods and run the risk of chipping the 
sharper edge of the inlay. 

Class 4. — Cavities in the proximate surfaces of the 
incisor teeth involving the loss of the mesial or distal 
angle, and its restoration. — In this class of cases the proxi- 
mate cavity is prepared, with the exception of its mesial 
angle, in the same way and with the same instruments as 
have been described, except that the anchorages in the 
labio-gingival and linguo-gingival angles are made deeper 
and stronger. That is, the axial wall is cut deeper into the 
dentin in the gingival portion to the lingual and to the 
labial than in its central area, for the purpose of sinking 
these anchorage points deeper into the substance of the 
dentin. 

The weak incisal angle is cut away to the labial groove, 
mesial or distal, as the cavity is to the mesial or distal. 
This groove, although not very apparent, is a weak line in 
the enamel at which it most often breaks, and it should 
always be included when the angle is so weak as to require 
removal. When this has been done, cut away the incisal 
edge of the middle lobe of the tooth, i. e., to the next labial 
groove, mesial or distal, with the corundum stone in the 
engine or with a small flat jeweler's file, cutting more from 
the lingual than the labial. The depth of this cutting 
should depend upon the thickness of the cutting edge of 
the tooth. If the cutting edge be thick and already some- 
what worn, very slight cutting is sufficient. If unworn 



102 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

and thin, the cutting should be greater. A small inverted 
cone bur, not more than i 8 o millimeter in diameter, is now 
caused to enter the dentin in the proximate cavity, close to 
the junction of the labial and lingual* enamel plates, and 
carried, by a series of cuts in which the bur is drawn out 
at the incisal edge, along the length of the incisal edge 
across the middle lobe, or as far as the incisal edge has 
been previously cut. In this cutting with the bur, the 
labial enamel plate should be left complete and the cutting 
done at the expense of the lingual enamel plate. After 
the first cut is completed, forming a groove, in which the 
bur should always reach fully into the dentin between the 
labial and lingual plates, the lingual plate should be cut 
away to very nearly or quite the depth of the cut by the 
bur. Then the bur should again be passed along the slight 
groove left, cutting it deeper, keeping close to the lingual 
rather than the labial enamel plate, forming a groove in the 
dentin between the enamel plates. In making this groove 
it is an object to leave as much dentin as possible sup- 
porting the labial enamel plate. The depth of the cutting 
toward the pulp of the tooth must be guided by the judg- 
ment of the operator, care being taken not to expose the 
pulp. But in these cases it is always better to expose 
and remove the pulp than to fill with an anchorage that is 
manifestly insufficient. The groove is the principal de- 
pendence for the incisal anchorage. This should be squared 
out with a fissure bur and its walls made parallel. No 
undercuts or pits are needed. A little broadening and 
rounding away where it joins the proximate cavity will 
make this connection stronger. In the incisal enamel walls 
formed in making this incisal step, both labial and lingual, 
the enamel rods incline toward the incisal, and these walls 
should take that form rather than be cut at right angles 
with the long axis of the tooth, and then the cavo-surface 
angle must be slightly beveled in order to give it greater 
strength. 

Teeth with thin, cutting edges are very difficult of man- 
agement in making incisal steps for the restoration of a 
lost or weak angle, because the gold built on them is too 
thin to have sufficient strength. In many of these cases. 



EXCAVATION OF CAVITIES BY CLASSES. IO3 

the incisal edge of all of the incisors, or only the centrals, 
may be ground away in imitation of normal wear, and the 
incisal edge thickened without injury to the appearance, 
In doing this it is well to remember that in very thin 
teeth the horn of the incisal pulp is likely to be long and 
slender, and the danger of exposing them in cutting the 
step is increased. 

In cases where there has been such wear of the incisal 
edges of the teeth that the dentin is exposed, the step 
should include all of the exposed dentin. In this case very 
little cutting from the lingual enamel plate will be needed, 
and generally none from the labial. In the management 
of this class of cases it should be remembered that in such 
large cavities the bulk of gold in close proximity to the 
pulp is liable, through its conductivity of thermal changes, 
to set up irritation that will destroy its vitality. In cases 
in which there seems to be imminent danger of this, it 
is better to remove the pulp at once. It is also better to 
remove the pulp at once than to run serious risk of losing 
the filling from insufficient anchorage in the effort to save 
the pulp alive. 

In all of these cases esthetic practice calls loudly for 
porcelain inlays instead of gold. There is no form of filling 
that mars the appearance of a tooth so much as the restora- 
tion of a lost angle with gold, unless, indeed, it is the 
restoration , of both angles of the same tooth. But the 
retention of inlays in these cases is the most difficult prob- 
lem facing the devotees of porcelain inlay fillings. The 
difficulty is to obtain a mass of porcelain large enough 
to give sufficient strength and at the same time secure satis- 
factory anchorage. While at present only a few well- 
selected cases promise good results with porcelain, it seems 
generally best to restore these with the lightest shade of 
platinum gold. 

Preparation of anchorage for restoration of the lost 
angle with gold after removal of the pulp of the tooth 
should be on entirely different lines. The weakened angle 
should be cut away to the first labial groove as before, but 
no step should be cut along the incisal edge of the tooth. 
Instead of this, the pulp chamber should be widely opened 



104 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

toward the incisal fully to the point of its horns, or, in 
most cases, extended further to the incisal. and the cut- 
ting finished so that the incisal wall is at right angles to 
the long axis of the tooth. Generally the dentin should be 
cut away well to the lingual so as to give good access to 
this portion of the cavity for, packing gold into this angle, 
and this should be made the retention to sustain the angle 
built on. The anchorage at the gingival should be cut 
similarly to that described for the preparation with the 
pulp alive, with the additional retention in the pulp cham- 
ber. This gives a more secure anchorage than the incisal 
step, and a restoration that gives a better appearance. 

One of the difficulties with this class of restoration is 
that in the course of years the incisal edge of the tooth will 
wear away more rapidly than the gold filling, and a notch 
is liable to form which has a tendency to force the filling 
out of the cavity. This is remedied in some degree by 
cutting the lingual enamel plate about a half millimeter 
further than the labial plate, leaving a square angle where 
the two plates join. This seems to prevent, in a large de- 
gree, the tendency to prying away. 

In any case of fillings of this character, a close watch 
should be kept, having the patient return once or twice 
per year for this purpose, if no other occasion requires, so 
that any protuberance of the filling beyond the incisal 
edge of the tooth may be dressed down and prevent pos- 
sible injury. In the author's practice, such fillings made 
for young people have been watched and occasionally 
dressed down until the whole incisal portion of the tooth 
had worn away, exposing the gold in the incisal portion of 
the anchorage. 

This class of cases is not suited to porcelain restorations 
because of the liability of discoloration of the remaining 
portion of the tooth, which will so often give an effect 
that will be worse from the esthetic standpoint than the 
restoration with gold. 

Class 5. — Preparation of cavities in the proximate sur- 
faces of bicuspids and molars. — The preparation of proxi- 
mate cavities in the bicuspids and molars, if estimated by 
the comparative number of failures in filling teeth, must 



EXCAVATION OF CAVITIES BY CLASSES. 105 

be regarded as the, most difficult of rilling operations. 
Therefore, more than usual attention should be given by 
the student to the specific plans and details of these opera- 
tions. The instruments used are almost exclusively the 
specials. There is very little that can be done advantage- 
ously with the ordinaries except some occasional cutting 
with the larger sizes. More cutting away of sound, firm 
dentin and enamel is required than in any other class of 
cavities. The proximating surfaces are broad, and for 
success in preventing recurrence of decay, it is required 
that these be cut away, so that the outlines of the cavity 
be free from near contact with proximating teeth, and laid 
in such position that they will be well cleaned by excur- 
sions of food over them in mastication. Also, in making 
fillings it is of the utmost importance that the contact be 
restored in normal form for the protection of the inter- 
proximate gum septum, that this may be retained in health 
and vigor. To do this effectually, it is required that these 
fillings be finished to the full mesio-distal breadth of the 
teeth. 

Case. — A right upper first molar has a decay in its 
mesial surface, which has been discovered by the patient 
because of a slight breaking away of the mesial marginal 
ridge, disclosing the cavity. Examination with the explor- 
ing instrument shows the cavity to occupy about half of 
the mesial surface occluso-gingivally and the middle two- 
fourths bucco-lingually in its extension beneath the enamel, 
though the enamel opening is very much smaller. 

Procedure. — In these cases it always becomes a ques- 
tion as to when the rubber dam and the Perry separator 
shall be adjusted. It may be done first, or it may be done 
after the cavity has been opened and the outline form 
roughly cut. But it must always be done before the final 
shaping and trimming of the walls and margins of the 
cavity is undertaken. 

Opening the cavity. — With straight chisel 15, preferably 
by mallet pressure, though hand pressure may be used, 
begin chipping away the mesial marginal ridge of enamel 
cverhanging the decayed area, first toward the buccal, and 
then toward the lingual, and continue until the enamel is 



106 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

found supported by sound dentin. In the cutting, espe- 
cially if done by hand pressure, the edge of the chisel 
should be set very close to the margin to be chipped, and 
the enamel cleaved off in little flakes, the direction of the 
pressure and the motion being almost in the line of the 
length of the enamel rods, but slightly inclined in a direc- 
tion to throw the chips off from the free surface into the 
cavity. The instrument must be very sharp to be effective. 
Then cut away the enamel toward the central fossa, as far 
as it can well be done by the chisel. At this point it is 
well to take the enamel hatchets 1 5-8-12, or 20-9-12 if there 
is sufficient room, and trim the overhanging enamel from 
the buccal and lingual walls of the cavity with a few 
strong, vigorous strokes, or the buccal wall may usually be 
cut with the straight or binangle chisel, using the enamel 
hatchet for the lingual wall. Then sweep the enamel 
hatchets around the gingival wall with a scraping motion, 
cutting to sound dentin. Note particularly that the enamel 
hatchet of the right bevel, to cut the lingual wall, should 
cut to the lingual in trimming gingival wall; while the 
one with the right bevel, to cut the buccal wall, should 
move to the buccal in cutting the gingival wall. If the 
cavity is shallow mesio-distally, this will incidentally 
remove most of the carious dentin ; but that is immaterial. 
If the cavity is very deep mesio-distally, no further effort 
should be made at this time to remove the carious dentin. 
The outlines of the cavity are exposed, and that is suffi- 
cient. The next procedure is to cut a step in the occlusal 
surface for the retention, and complete the outline of the 
cavity in this direction. Select an inverted cone bur not 
more than one millimeter in diameter, and, placing its shaft 
nearly or quite parallel with the long axis of the tooth, 
enter the bur sidewise into the dentin just beneath the 
dento-enamel junction, and draw it slowly to the occlusal 
surface of the enamel. Repeat this motion in cut after cut, 
following the mesial groove distally to the pit in the cen- 
tral fossa. Then with straight chisel 15 or 20, or with the 
enamel hatchets, chip away the enamel from either side of 
the slot formed by the bur. Now pass the bur along the 
slot again, first pressing it strongly to the buccal so as 



EXCAVATION OF CAVITIES BY CLASSES. IO7 

to undermine the enamel, then pressing to the lingual, and 
again chip away the enamel both to the buccal and to the 
lingual. Repeat this until the step occupies the full middle 
third of the occlusal surface bucco-lingually to and includ- 
ing the pit in the central fossa. Now the buccal groove 
and other sharp grooves should be cut out as in the 
preparation of occlusal cavities. This gives a step with a 
fiat pulpal wall and definite angles with its surrounding- 
walls, and of perfect retentive form. 

Next the proximate portion of the cavity must be 
extended. When the buccal and lingual walls have been 
cut away to sound dentin, it is often necessary to extend 
them further. They should be cut well into the embrasures, 
both buccally and lingually, so that the cavity margin will 
be removed from near contact with the proximating tooth. 
When much sound dentin must be removed to accomplish 
this, it is easier to do it by introducing an inverted cone 
bur into the dentin against the dento-enamel junction, 
about the bucco-lingual center of the length of the gin- 
gival wall, and carry it buccally to the buccal wall, squaring 
out the bucco-gingival angle, and then, drawing it along 
the buccal wall toward the occlusal surface, undermine the 
enamel along this wall also. Then the undermined enamel. 
is easily cut away with the enamel hatchets, or by clipping 
with the chisel used from the mesio-buccal angle of the 
tooth through the embrasure. Cut out and extend the 
linguo-gingival angle of the cavity and the gingival wall 
in the same way and using the same instruments. A good 
rule as to the extent of the extension is to cut the lingual 
wall to a line where its margin will be in view, past the 
proximating tooth when looking across the central incisors 
at the median line, and make the extension of the buccal 
wall to correspond. In some instances it will be found 
that after this extension has been made, a line of super- 
ficial injury to the enamel extends beyond the margin of 
the cavity at one or both of its gingival angles. This 
should be carefully looked for, and when found, the cavity 
should be further extended so as to include the injured 
portion. 

It must now be determined whether or not the gingival 



108 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

wall has been sufficiently extended gingivally for its mar- 
gin and its buccal and lingual angles to be covered by 
the free margin of the gums when the filling is finished. 
If not. it must be extended further to the gingival. This 
is difficult to do entirely with hand instruments, but by 
using an inverted cone bur with its flat end against the 
gingival wall, it is inclined sufficiently for its corner to 
engage, and carried, within the dentin, along the dento- 
enamel junction to the bucco-gingival angle, then inclined 
in the opposite direction it is carried into the linguo- 
gingival angle. In this cutting be very particular that the 
bur follows the dento-enamel junction and that it does 
not cut deeply into the dentin. The object always is to 
avoid very deep cavities. In this way the enamel to the 
gingival is undermined and may be much weakened by 
passing the bur a few times with hard pressure against its 
inner side. It may then be removed with the enamel 
hatchets and the gingival wall be made horizontal and 
smooth. Its angle with the axial wall should be sharp and 
definite. 

Any decay remaining on the axial wall is now removed 
with spoons 20-9-12. or in this particular position with 
the discoid. The enamel walls are now planed to form. 
In all of the occlusal portion these may be perpendicular. 
On the buccal, the enamel wall must be inclined strongly 
to the buccal to agree with the enamel cleavage. The 
lingual enamel wall must be inclined similarly to the 
lingual. The inclination given the buccal and lingual 
enamel walls will depend upon their relations to the angles 
of the tooth. Generally the plane of the enamel wall should 
be perpendicular to the surface of the tooth at the par- 
ticular point where the enamel margin is laid. The appar- 
ent inclination will therefore vary with its position. If, 
because of extension of decay in that direction, the cavity 
margin is carried far around the angle onto the buccal 
surface, the plane of the enamel wall will be nearly or 
quite in the bucco-lingual plane of the tooth. If a less dis- 
tance, the inclination will be less. The gingival enamel 
wall should be inclined a little to the gingival. 

The cavo-surface angle of all parts of the cavity outline 



EXCAVATION OF CAVITIES BY CLASSES. IO9 

must now be beveled. All except the gingival and the 
rounding of the bucco and linguo-gingival angles may be 
done with the chisels. A special instrument is required 
for beveling the gingival cavo-surface angle, the gingival 
margin trimmers 20- (80) -9- 12. for mesial cavities and 
20- (95) -9-12 for distal cavities. These instruments are used 
for no other purpose whatever. They have the angle of 
the edge cut purposely for making this bevel. A few 
strokes lightly made, and carried around the angle first 
with the right-hand instrument in the one direction and 
then with the left-hand instrument in the other direction, 
are sufficient. 

In the finished cavity the dentin walls to the buccal and 
lingual should generally not be in the same plane with the 
enamel walls, but in cavities of ordinary size they should 
be very nearly parallel with each other and in the mesio- 
distal plane of the tooth. In the occluso-gingival direc- 
tion they should be parallel with the long axis of the 
tooth and parallel with each other. 

The cavity now only requires the toilet to be made, 
to be ready for filling. 

How r ever, most persons would prefer some convenience 
points in the gingival portion of the cavity for retention 
in starting a gold filling. These are made, one in the 
axio-bucco-gingival : angle, and one in the axio-linguo- 
gingival angle, by pressing an inverted cone bur into the 
dentin slightly and drawing it a short distance to the 
occlusal along the bucco-axial line angle and the axio- 
iingual line angle respectively. These give sufficient 
starting points and will retain the filling while the building 
of this part is in progress. 

Variations due to position. — The variations of procedure 
due to position of the teeth in the mouth and the different 
degrees of exposure of the parts to view and to approach, 
relate mostly to the second and third molars and to the 
lower bicuspids. The upper first bicuspids are usually so 
well exposed that both the mesial and distal cavities are 
easily reached, and except that the smaller cutting instru- 
ments, as the 1 5-8-12 and 10-6-12 enamel hatchets and cor- 
responding chisels and spoons, are necessary, the instru- 



IIO THE TECHNICAL PROCEDURES IN FILLING TEETH. 

ments and the instrumentation will be the same. Neither 
is it often necessary to make any variation in distal cavi- 
ties in the first molar or mesial cavities in the second molar, 
above or below. 

In distal cavities in the second molar and mesial cavities 
in the third molar it frequently happens that the inverted 
cone bur can not. be made to approach the cavity at the 
proper angle to square out and extend the bucco- and 
linguo-gingival angles. In these cases the bur in the 
contra-angle hand-piece may be substituted, or the cutting 
may be done entirely with the hand instruments. How- 
ever, in the greater number of cases in which distal cavities 
in the second molar are excavated at the same time with 
mesial cavities in the third, the straight hand-piece may 
be used for both. This is facilitated by cutting the step 
in the second molar first and carrying it well to the mesial. 
This gives additional room for the application of instru- 
ments to the distal portion of the cavity and also to the 
mesial cavity in the third molar. 

Occasionally there is difficulty in so placing the inverted 
cone bur as to begin cutting the step in the occlusal por- 
tion from the distal cavity of a second molar. The 
approach is such that the shaft of the instrument is 
inclined so much to the distal that the bur cuts the enamel 
from the surface inward, instead of cutting the enamel 
from within outward, and for this reason will not cut well. 
The proper position of the bur may be obtained with the 
contra-angle hand-piece, but if the enamel proves very 
hard this instrument does not work well. It is better in 
such cases to enter the occlusal surface through the pit 
in the central fossa in the usual way of opening pits, or 
with a drill, if the pit is fully closed, and then enter the 
inverted cone bur at this point and cut to the distal along 
the line of the distal groove until the distal cavity has been 
entered. This slot may then be broadened to the buccal 
and to the lingual in the usual way to form the step. 

The approach to distal cavities in the upper second 
molars is often somewhat from the buccal, and to facilitate 
this approach in building the filling the buccal wall should 
be strongly inclined to the buccal, whenever this can be 



EXCAVATION OF CAVITIES BY CLASSES. Ill 

done without very positive detriment to the case. One 
should never neglect to obtain such form as will render the 
filling of the cavity convenient. 

In the lower molars, especially those that have a strong 
lingual inclination, the form of the distal cavity may be 
made for filling with reverse pluggers. In this case the 
buccal wall may be cut parallel with the long axis of the 
tooth and the gold packed against it entirely with the 
reverse plugger. 

The greatest difficulty is met with in distal cavities in 
lower bicuspids that have a strong distal and lingual 
inclination. It is in these that a contra-angle hand-piece 
and the reverse pluggers are most needed. These teeth 
are often small and the crowns long and decayed far to the 
gingival. They are difficult to reach with direct instru- 
ments. In these cases at least two teeth to the distal 
should be included in the rubber dam. Even if the first 
and second molars are lost, the rubber should include the 
third molar, to give good room for the use of the mouth 
mirror, for light, and to hold the rubber out of the way of 
instruments. It will then be found that the cavity is 
easily reached with hand-cutting instruments and the 
contra-angle hand-piece, and is readily filled with reverse 
pluggers after having attained facility in their use. In the 
absence of reverse pluggers much of the filling must be 
made by hand pressure. The form of the cavity should 
not differ materially from the forms produced in other 
teeth. If, however, it is decided that direct mallet force 
is to be employed to the greatest possible extent, the disto- 
buccal angle of the tooth should be boldly cut away suffi- 
ciently to give access to the gingival wall and the greater 
part of the cavity walls generally, and the step carried 
close against the mesial marginal ridge. This will allow 
a direct approach from the disto-buccal to all of the cavity 
walls except the axio-bucco-gingival angle, which must be 
filled by hand pressure. 

Preparation for Porcelain Inlays. 

With the experience thus far had with porcelain 
inlays, it may be said that the general rule should be that 



112 THE TFXHXICAL PROCEDURES IN FILLING TEETH. 

cavities occurring in the proximal surfaces of the bicuspids 
and molars should be filled with metal ; gold or amalgam. 
But many cases occur, especially in the upper bicuspids 
and less frequently in the upper first molars, in which 
decay has so undermined the mesial portion of the buccal 
cusp, and the prominence of the teeth is such that a gold 
filling will show badly when the undermined enamel wall 
has been properly cut away in the preparation of the 
cavity. These cases seem to call for porcelain inlays for 
the better esthetic effect The general rules for the 
preparation of such cavities for porcelain inlays will be 
almost the same as for gold, except that there must be no 
beveling of the cavo-surface angle in any of its parts 
except along the gingival. Neither should there be any 
undercuts or convenience points such as are made for 
starting gold fillings. Margins cut at right angles with the 
surface of the tooth at every point should be the rule, for 
in this case they will be parallel with the length of the 
enamel rods. In the mesial portion of the cavity, the 
buccal and lingual dentin walls should be cut in a line with 
the long axis of the tooth, or flared a little toward the 
occlusal, so that a matrix properly fitted will be easily 
removed to the occlusal. The gingival dentin wall should 
be perfectly flat, in the horizontal plane, and as broad as 
the conditions will allow, in order to give the firmest seat 
to support the inlay. The occlusal portion of the cavity 
and the steps should be prepared on the general prin- 
ciples laid down in the preparation for inlays in occlusal 
surfaces. In this case, however, it becomes especially 
important that the step in the occlusal portion of the tooth 
be so prepared that a slightly dovetailed form or parallel 
walls mesio-distally will support the inlay from being dis- 
placed or. toward the proximating tooth. This step should 
be as broad and deep as the conditions will allow in order 
to give the greatest possible strength to the inlay, and the 
dovetail so cut that a matrix snugly fitted to its walls will 
readily slip out to the occlusal. 

In case the cusp of the tooth has been so weakened by 
decay as to be in serious danger of being broken by the 
force of the occlusion, it should be cut away at once. In 



EXCAVATION OF CAVITIES BY CLASSES. II3 

some cases this cutting may extend only just over the 
point of the cusp enough to give a good body of porcelain 
on the cusp. At this point the enamel rods are so inclined 
toward the cusp that the cleavage will allow of a some- 
what acute cavo-surface angle that will be strong and 
safe, so that the porcelain, after rounding over the cusp, 
may have a strong obtuse angle against the enamel. Other 
cases will not be favorable for this, and will require that 
more of the cusp be cut away in order to give sufficient 
strength, possibly to one-third or one-half the length of 
the tooth. In this latter case, unless the pulp of the tooth 
has been removed, it will become very difficult to obtain 
sufficient anchorage in bicuspids because of the lack of 
sufficient tooth substance in which to make a good anchor- 
age. In such a case it will often be better to remove the 
pulp in order to use the pulp chamber for additional 
anchorage. Then the horns of the pulp chamber may be 
cut out to the occlusal for the purpose of forming the 
anchorage and the whole length to a level with the gingival 
wall used. 

In case there is a mesio-occluso-distal cavity that has 
weakened the tooth badly, in a bicuspid with pulp removed, 
both cusps may be cut away about one-third the length of 
the tooth and a porcelain inlay built up on a matrix 
formed to the prepared cavity that will replace the entire 
occlusal surface. In such a case the greatest care must be 
exercised in forming the anchorage, and also in so arrang- 
ing the detail of the cavity form that the body of the porce- 
lain inlay will be particularly thick and strong. 

In these cases I am supposing that the operator has 
destroyed and removed the pulp of the tooth himself under 
conditions that will certainly prevent the future discolora- 
tion of the remaining parts of the tooth ; or under condi- 
tions in which no products of decomposition have found 
their way into the dentin. In any case where there has 
been abscess, or in which the pulp chamber has been open 
to the fluids of the mouth, we may expect that products of 
decomposition have been absorbed into the dentin that will 
cause more or less discoloration and destroy the esthetic 
effect of a nicely fitted inlay. 



114 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

Management of Weak Cavity Walls in Molars and 
Bicuspids. 

In the lower molars, especially when the contacts are 
very broad, the proximate cavities are likely to be deepest 
toward the lingual, and to burrow extensively along the 
lingual dento-enamel junction. In these cases the lingual 
wall will be weak at the mesio- or disto-lingual angle of 
the tooth, and this not infrequently extends to the cen- 
tral line of the lingual surface. In all such cases the 
removal of the angle, including the lingual cusp, mesial or 
distal, is imperative. This should usually be done by 
catching the enamel near the margin of the cavity with 
the sharp edge of binangle chisel, and with a pull toward 
the cavity, split it off. This may be thrown off, chip after 
chip, easily, until a point is found at which it is supported 
by sound dentin, or strong enough for a filling to be built 
against it and restore the lost contour with safety. 

In occlusal cavities in these teeth, the central pit in 
which decay begins is much nearer the lingual than the 
buccal surface, because of the rounding of the buccal sur- 
face toward the occlusal. For this reason the lingual 
enamel plate is often undermined and weakened in its cen- 
tral portion mesio-distally, even in cavities that are not 
very much extended in other directions. In these cases 
the lingual groove should be cut out over the crest of the 
marginal ridge and the marginal ridge itself removed well 
toward both the disto- and mesio-lingual cusps. The gap 
formed in the lingual wall may be built over and the form 
of the tooth restored. In both these cases the enamel wall 
remaining should be smoothly cut at right angles to the 
axial plane of the tooth. 

In the upper molars the buccal wall is more often the 
weak wall. This does not so often occur in case of occlusal 
cavities, though it is not infrequent. But often in mesial 
cavities the mesio-buccal angle is found badly undermined 
by decay. If the decay has spread along the dento-enamel 
junction or if the decay has reached the enamel and left 
it unsupported, the cusp should be cut away at once and be 
restored with the filling material. Often in mesial cavities 
decav will have extended far to the buccal without under- 



EXCAVATION OF CAVITIES BY CLASSES. H5 

mining the cusp, in which case an extension of the enamel 
margin will not meet the requirements without the removal 
of the cusp. In such cases the enamel wall should be fin- 
ished in the bucco-lingual plane. 

In upper first molars, with large disto-lingual cusps, the 
contact point is often toward the lingual, and caries of the 
distal surface is therefore likely to begin in such position 
as to undermine the linguo-distal cusp and weaken the 
lingual wall of the cavity. Also the disto-lingual groove 
is usually deep and sharply sulcate in these teeth, and 
forms a very weak line in the enamel. Therefore, unless 
the lingual enamel wall is found well supported by dentin, 
the cusp should be removed and the enamel cut away to 
the disto-lingual groove, and the cutting continued toward 
the gingival until good strength is found. 

In the upper bicuspids, the buccal angles are most likely 
to be undermined first because of the contact point being 
well toward the buccal, and the first beginning of decay 
occurring just to the gingival of it. When the angle, either 
mesial or distal, is so undermined that the enamel is unsup- 
ported by dentin, it should be cut away to the buccal 
groove. This groove, though generally so well closed on 
the buccal surfaces of the bicuspids as not to be very 
apparent, is still a Aveak line in the enamel, at which it is 
more than usually liable to break. 

In addition to these special points of liability to weak 
walls, decay is liable to burrow in any direction, causing 
weak walls in other, and occasionally in unusual, positions. 
Any such are to be treated upon the general lines that 
have been indicated. It should be a rule that when a wall 
requires cutting away because it has been weakened by 
decay, and, in the cutting, a developmental groove is 
approached, it should be cut to, or past, the groove. 

In mesio-occluso-distal cavities in the upper bicuspids, 
from which the pulp has been removed, the whole of the 
occlusal enamel plates .should be removed to. and slightly 
over, their crests to the buccal and lingual, and be restored 
by filling material. This will bring the work of mastication 
entirely upon the filling material and prevent the weakened 
cusps from being split off. 



Il6 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

Separating Teeth. 

In filling proximate cavities in which the proximating 
tooth is present, provision must be made before the filling 
is begun for finishing the filling. If the teeth originally 
made a close contact, it is necessary to separate them, or 
lift them a little apart in order that we may finish the 
hlling to the full mesio-distal breadth of the tooth and 
restore the contact in correct form, preserving the full 
breadth of the interproximate space. This is necessary to 
the maintenance of the health of the interproximate gin- 
givae, the gums, the peridental membranes and the teeth. 
If the contact of the filling with the proximating tooth is 
not made in correct form, food will be held between the 
teeth and will be crowded upon the interproximate gum 
tissue, causing inflammation and absorption, and finally 
injure the gums and peridental membranes, perhaps caus- 
ing incurable disease and final loss of the teeth. Or, by 
forming a pocket in the gum tissue about the gingival 
margin of the filling, in which debris undergoes fermenta- 
tive decomposition with acid formation, recurrence of decay 
is caused which destroys the filling and the tooth. These 
considerations, derived from careful clinical observation, 
render it imperative that we make provision for finishing 
proximate surface fillings to very exact form by first 
separating them sufficiently to give room to do this work. 

In all ordinary cases the separation of teeth to gain 
room for finishing is done best by the use of the Perry 
separator. This instrument simply catches the two teeth 
by their necks and lifts them apart by turning a screw. 
The separation required is done with the least pain pos- 
sible, is done at once, and without causing especial soreness 
of the teeth. Generally the separator should be applied 
before the filling is begun and the teeth separated suffi- 
ciently at once. Occasionally, and especially with the 
molar teeth, when the teeth are very firm, they are difficult 
to move sufficiently. If in such cases the separator is 
forced very tight, the instrument springs instead of separat- 
ing the teeth. But when it is allowed to remain and the 
filling is proceeded with, it is found that when the filling 
has been built and is ready for finishing the continuous 



SEPARATING TEETH. II7 

spring force of the separator has caused them to yield 
sufficiently. We should make note of this and be careful 
not to force the separator too hard upon the single-rooted 
teeth, for if we attain the full separation required at once 
we will find when the filling is completed that we have 
separated the teeth much more than was necessary. All 
of this you will learn intimately by observation in the 
infirmary. 

When the separator is applied, if the bows do not rest 
firmly upon the teeth they should be made firm by prop- 
ping them with gutta-percha. To do this the gutta-percha 
is softened by heat and placed between the bows of the 
separator and the occlusal, or incisal, surfaces of the teeth, 
and a little time allowed for it to harden before finishing 
the separation. This should be done at once when the 
separator has been made just tight enough to retain its 
position well, for in the after tightening of the screws 
there is a tendency for the claws of the separator to slip 
further to the gingival and, coming against the attach- 
ment of the peridental membrane to the neck of the tooth, 
cause unnecessary pain and some injury. This also pre- 
vents movements of the separator while operating, which 
causes the patient much pain and inconvenience. 

The principal objections to the Perry separator are, 
first, that in the sets of six, as usually sold, there are not 
a sufficient number of forms to accurately fit all kinds of 
cases ; second, that they are very expensive instruments ; 
and, third, that there^ are many irregular cases with teeth 
so out of position that they can not be made to fit. This 
last objection will naturally attach to all mechanical devices 
for this purpose. The universal Perry separator now on 
the market answers the purpose of the set of seven very 
well, and obviates the necessity of purchasing so many 
instruments. It is a little more clumsy in use than the 
other instruments, and at first its adjustment seems more 
awkward. However, when one has attained some skill in 
its use it will be found to fit more places than the whole 
set of seven. It is therefore the better instrument to use. 
The principal point in its use is to learn to adjust the 
points, or claws, to the right width for the particular case 



Il8 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

in hand. When this has been done its use is not more 
difficult than the use of any one of the set of seven. The 
most real difficulty with the instrument is that the crowns 
of some teeth are too long for the claws to reach the right 
point on their necks. A second instrument, a little longer 
in the reach, ought to be made. 

When the teeth are very irregular in the arch, other 
means of separation often have to be devised. Wedges of 
wood may sometimes be used, or cotton can be crowded 
tightly between the teeth and tied over or about the con- 
tact point with a ligature and accomplish a sufficient 
separation within a few days. Drawing slips of rubber 
between the teeth and cutting the ends short is a very 
effective method of slow separation, but is apt to make the 
teeth very sore. In using rubber for separating great care 
should be had that the rubber does not press upon the gum 
septum. This not only creates unnecessary soreness, but is 
liable to do great injury to the gum septum. 

A method that is excellent for very slow separation in 
the molars and bicuspids is to excavate the cavity roughly 
and moisten its surfaces with eucalyptol to make the 
gutta-percha adhere to the walls, and then fill it solidly 
with gutta-percha, filling the interproximate space solidly 
against the proximating tooth. In doing this an instru- 
ment of some form should be placed firmly in the inter- 
proximate space against the gum septum while the gutta- 
percha is being packed, and afterward removed. This will 
protect the gum septum from being absorbed by the con- 
tinued pressure of the gutta-percha. This point should 
never be neglected, as a full gum septum is necessary to 
the health of the parts, and it should be carefully pro- 
tected against injury. When the patient is discharged 
temporarily he should be directed to make vigorous use 
of the tooth in chewing. The impact of the food will cause 
the gutta-percha to spread and carry the teeth apart suffi- 
ciently within a week or two. This is a very effective 
method of slow wedging in cases in which the teeth have 
dropped together from loss of the contact point, and has 
the merit of moving the teeth without creating soreness. 
But it must be remembered that the teeth are separated by 



FILLING MATERIALS. 119 

expanding- the gutta-percha by heavy chewing upon it. If 
the patient does not do this it will fail to separate the 
teeth. Obviously this plan cannot be used when there is 
no tooth in the opposite jaw that will occlude on the gutta- 
percha. 

In cases requiring much movement it can be hurried a 
great deal by first putting on the Perry separator and lift- 
ing the teeth apart as much as possible, and making the 
gutta-percha filling, as indicated above, and giving suffi- 
cient time for the gutta-percha to become fully hard before 
removing the separator. This may be repeated at inter- 
vals of two or three days until sufficient separation has 
been obtained to fully restore the width of the interproxi- 
mal e space and mesio-distal breadth of the tooth. 

It occasionally happens that a tooth has lost the greater 
part of its crown, and the teeth on either side have dropped 
together over it, so that the restoration of the form of the 
crown is impossible without a very considerable separa- 
tion. In this case the breadth of two interproximate spaces 
are to be recovered by separation. If the lingual and buccal 
walls are still sufficiently strong, it is still possible to 
accomplish this with gutta-percha, but when they are not it 
is better to cut away most of the remaining portions of the 
crown, and insert a piece of hard, dry hickory wood in 
place of the missing crown in such a way that the length 
of the grain of the wood shall be from buccal to lingual. 
'Jnis should be cut to fit snugly between the two teeth on 
either side, and forced into position. This will absorb 
moisture from the saliva, and swell and slowly carry the 
teeth apart. The wood should be exchanged for a new 
piece once in two or three days, and continued until space 
is gained for the restoration of the full mesio-distal 
breadth of the crown. This plan is especially useful in 
gaining the necessary space for restoration with artificial 
crowns, as well as in building up badly decayed teeth with 
metal. 

Filling Haterials. 

The filling materials at present in use for permanent 
operations are, gold, which holds the first place, and amal- 
gam, which holds a second place, in value. Added to these 



120 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

many would reckon tin as holding a place equal or nearly 
equal to amalgam, but the general judgment of the dental 
profession would seem to consign tin to a very obscure 
position as a filling material, as nowadays very few per- 
sons make much use of it. Recently porcelain inlays are 
assuming prominence as a filling material, and are being 
pushed to the front by many skillful operators. 

The filling materials for temporary operations are the 
cements, especially the oxy-phosphate of zinc cements, and 
gutta-percha. 

The qualities most desired in a filling material for per- 
manent operations are indestructibility in the fluids of the 
mouth, adaptability to the walls of cavities, freedom from 
shrinkage or expansion after having been made into fill- 
ings, and resistance to attrition and the force of mas- 
tication. 

The qualities of secondary importance are color, or 
appearance, non-conductivity of the thermal impressions, 
and convenience of manipulation. 

Of these first qualities gold seems to possess in much 
the greatest degree those most essential. It is perfectly 
indestructible in the fluids of the mouth; it is very per- 
fectly adaptable to the walls of cavities; it is free from 
objectionable shrinkage or expansion; its resistance to 
attrition is good and it resists the force of mastication 
better than amalgam. 

Of these second qualities gold is not so good. It con- 
ducts thermal impressions strongly, its yellow color is 
objectionable, and it is not very convenient of manipula- 
tion. Indeed, it may be said of this last quality, that its 
successful manipulation requires much study and careful 
experience, and yet, when this study is given it and the 
required experience has been obtained, it may be worked 
into fillings more perfectly than any other material. 

Amalgam, as alloys for which are at present produced 
by the best makers, is possessed of the first qualities in a 
high degree, yet inferior to gold in all. It is not com- 
pletely indestructible in the fluids of the mouth, but 
oxidizes or sulphurets slightly, just sufficient to change its 
color from a silvery whiteness to brown or black. Its 



FILLING MATERIALS. 12 1 

adaptability to the walls of cavities is not so perfect as that 
of gold, though apparently so easy when used in a very 
plastic state as to be very deceptive. Much careful study 
and experience are required to work it well. Its resistance 
to attrition is good, but its capability of resistance to the 
force of mastication is less than that of gold. 

Much of the difficulty attending the use of amalgam 
arises from a lack of an understanding of its qualities. It 
is a metallic compound in which each element entering 
into its composition exerts its special influence upon the 
qualities of the product; and these qualities are varied 
with every little change in its composition. These changes 
of qualities and the laws controlling them are as yet under- 
stood by but few makers of amalgam alloys, and are not 
generally understood by the dental profession. For these 
reasons dentists are in constant danger of using amalgam 
alloys with which good fillings can not be made because of 
shrinkage or expansion of the material after being made 
into fillings. 

In secondary qualities its color is bad, so bad indeed 
that it should never be used in the anterior teeth on this 
account. Its conductivity of thermal changes is nearly 
equal to that of gold. Its working qualities render it much 
more convenient than gold in very large and difficult cav- 
ities. It can be placed much quicker, less expenditure of 
force is required, and much less time, but ordinarily per- 
fection of adaptation is less certain. 

Forms of Gold. 

Gold is prepared in the form of foil for filling teeth. 
This foil is prepared in various thicknesses, which are 
rated on the basis of the number of grains in the sheet four 
inches square. If a sheet of this size contains two grains 
it is called No. 2 ; if three grains, No. 3 ; of four grains, 
No. 4, and so on up to what is known as the heavy foils, 
such as Nos. 30, 60, 120, etc. 

Gold is also prepared for use in filling teeth in the 
crystalline form. These crystals are put up in various 
kinds of masses, with about as many names as there are 
makers, and in these forms possesses certain desirable 



122 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

qualities, especially convenience of manipulation. In any 
of these forms, however,, it is much less readily kept in 
good working condition than foil, and for this reason is 
not so certain in its working properties. It often fails to 
veld perfectly, and especially it is often unreliable in 
adaptation to the margins of cavities. Great effort has 
been made to bring this form of gold into general use,, but 
the general judgment of the dental profession has seemed 
to be against it. for foil has always maintained its posi- 
tion as the form of gold most used. 

Welding Properties of Gold. 

Gold prepared in the form of foil or crystals welds per- 
fectly in the cold state when clean surfaces are pressed 
into contact. It is the only metal which has this property 
111 a high degree. In order that the welding property may 
be successfully used the surfaces of the gold must be clean. 
As this property of gold is readily lost by improper care. 
it is well to know intimately the conditions of the develop- 
ment of it,, and the loss of it. 

All metals,, except those known as the noble metals, 
oxidize quite readily when exposed to the air: that is. they 
attract the oxygen of the air and unite with it to form a 
film of oxide upon the surface. This prevents the contact 
of clean surfaces and therefore prevents welding. Gold, 
silver, platinum and mercury do not oxidize in this way, 
and it is for this reason that they are called noble metals. 
Silver and platinum do. however, attract oxygen to their 
surfaces in the form of a transparent film of condensed gas 
sufficient to prevent their surfaces from coming in contact. 
which prevents them from welding cold. Gold does not 
attract oxygen nor nitrogen to its surface and it is for this 
reason that it can be welded cold. Gold does, however. 
attract to its surface certain gases that are often present 
in our atmosphere in such quantities as to prevent its sur- 
faces from coming in contact, and destroy, temporarily or 
permanently, its welding properties. Some of these gases 
are such as will be removed from the surface of the gold 
by volatilization when heat is applied (by annealing), ren- 
dering the surface again clean with restoration of welding 



FILLING MATERIALS. 127, 

property. Other gases, notably those of the sulphur and 
phosphorus groups, condense upon the surface of gold 
and refuse to volatilize by heat, and in that case the weld- 
ing property of the gold is permanently destroyed. In 
these cases it seems probable that compounds in the form 
of fixed salts — non-evaporable — are formed on the surface 
of the gold. 

These general facts with regard to gold may readily be 
illustrated by a few simple experiments, which any one can 
perform. Ammonia is strongly attracted to gold. Place 
a small quantity of spirits of ammonia, or of aqua ammonia, 
in a large glass jar. The ammoniacal gas from this will 
till the space above the liquid. Now take a rope of gold 
which has been annealed and the welding property of which 
is perfect, and swing it by a thread above the liquid in the 
jar and replace the cork. In fifteen minutes remove the 
gold and try its welding property. It will not weld any 
more than so much tissue paper. If it is swung above 
chlorine water the welding property will be completely 
destroyed in two minutes. Now reanneal these ropes of 
gold ; the welding property is completely restored. 

How are we to know that this effect is produced by a 
condensation of gas on the surface of the gold? Place the 
gold first in chlorine gas for ten minutes, and then transfer 
it to ammonia for an equal time. Now, as these two gases 
unite to form a volatile salt, ammonium chloride, which 
readily crystallizes upon any cold substance, place the gold 
thus treated in a long test tube, and heat it quickly over 
a bunsen burner. Immediately white fumes begin to leave 
the gold, and these crystallize in a white ring on the colder 
portion of the test tube. Chemical examination of these 
crystals shows them to be ammonium chloride. This could 
occur only by the condensation of the gases on the gold, 
and the amount formed shows this condensation to be in 
very considerable quantity. The experiment may be 
varied by placing the gold first in the gaseous ammonia, 
and then transferring to the chlorine, but in this case there 
will not be so large an amount of the ammonium chloride 
formed, for the reason that the ammonia is not condensed 
on the gold in so large a quantity as the chlorine. 



124 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

In this experiment the salt formed is volatile, and the 
gold is readily cleaned by heat. But suppose the salt 
formed were a fixed salt that we can not volatilize by the 
annealing temperature ; then the welding property of the 
gold is permanently destroyed. This is what often occurs 
when the gold is not well protected. Now one of the prin- 
cipal reasons why the crystalline forms of gold are more 
difficult to keep in good condition than foil is the fact that 
the crystals form a sponge that more readily takes up and 
holds gases. 

By careful experiment it has been found that acid gases 
are most likely to permanently obscure the welding prop- 
erty of gold : hence, if the gold be kept in an atmosphere 
containing a liberal per cent of ammonia, ammonium salts 
will be formed on the gold. These salts are readily volatile : 
hence, gold so kept will always be readily cleaned by an- 
nealing and its welding property restored. 

We may use gold, non-cohesive or cohesive, as we 
choose, from the same book, or the same sheet, by simply 
keeping it in a drawer containing a small bottle in which 
a bit of sponge, punk or cotton is placed and occasionally 
saturated with spirits of ammonia. Used without anneal- 
ing this will be perfectly non-cohesive, or, when annealed, 
will be perfectly cohesive. This should be taken advantage 
of in keeping gold in good condition for use in either form. 

Annealing Gold. 

Gold is annealed to develop its welding property. This 
annealing is not for the purpose of softening the metal, as 
in annealing plate, but for the purpose of cleaning the sur- 
face of the gold by volatilizing any gaseous film that may 
have collected upon it. This purpose is explained suffi- 
ciently in the preceding article. The best means of accom- 
plishing this will depend somewhat upon circumstances. 
For the general work of filling teeth the annealing is very 
well done in the flame of the alcohol lamp or the flame of 
a small bunsen burner. The element of time is important 
in annealing, particularly if the annealing is done at low- 
temperatures, for the gases are not driven off at once un- 
less a full red heat is obtained. Therefore, in annealing 



FILLING MATERIALS. I25 

in the flame the gold should always be brought to a glow, 
and so held for a moment or two. It is also necessary to 
the best results that every particle of the gold be brought 
to a glow. In taking up the gold with the pliers, that por- 
tion of it that is caught between the beaks, and that very 
close to the beaks, will not be heated sufficiently to develop 
its welding property. This will introduce into the filling 
spots of failure to weld and greatly impair the strength 
of the work. For this reason great care should be exer- 
cised in annealing to see that all parts of the gold are 
brought fully to a glow. This is especially important when 
a corner is to be built up, as in the restoration of the angle 
of an incisor, or when a very solid surface is to be made, 
as upon the occlusal surface of a molar that will receive 
severe wear. Pitting of the surface of fillings is in a large 
degree the result of the introduction of bits of gold that 
have not been sufficiently annealed. To prevent the pos- 
sibility of this it is well to first anneal one part and then 
lay down the piece and catch it at another point and anneal 
again. 

While the gold should be heated to redness, it should 
not be heated to the melting point. This ruins the plas- 
ticity of the foil and makes it impossible to properly con- 
dense it. To avoid these difficulties the gold may be an- 
nealed upon a tray over the flame of the lamp. A number 
of devices for this purpose can be had, most of which are 
convenient and effective. The tray may be made of metal, 
of porcelain, or of mica ; it does not seem to make much 
difference which is used. In annealing in this way the gold 
may conveniently be exposed to the heat for a considerable 
time, and therefore a full red heat is not necessary to the 
complete development of the welding property, so that 
there is no danger of hardening the gold by melting por- 
tions of it. However, the heat must closely approach the 
point of redness to be effective. Another advantage is that 
all parts of the gold will become annealed. 

The disadvantages of this method are the presence of 
such an apparatus upon the bracket which is needed for 
operating instruments, and that the gold spread upon the 
annealing tray is liable to movement by every motion, or 



126 THE TECHNICAL PROCEDURES IX FILLING TEETH. 

in the effort to lift pieces from it, and roll together and 
stick to each other in such a way as to cause much annoy- 
ance and delay in handling it. Much of this annoyance 
can be avoided by having a tray that is so roughened as to 
prevent the rolling or sliding of the gold. The electric 
rnnealer, lately introduced, is the most perfect appliance 
yet devised for this purpose. Its use. however, requires the 
electric attachments and arrangements for the control of 
the current. 

Filling with Gold. 
In tilling teeth, cohesive gold or non-cohesive gold may 
be used, or the cavity may be partly filled with non-co- 
hesive gold and finished with cohesive gold. 

Filling with Non-Cohesive Gold 

Filling with non-cohesive gold for the entire cavity is 
practiced but very little nowadays, apparently for two 
reasons. It requires the development of a different order 
of skill from that required for cohesive gold, which is 
somewhat difficult to master, and it cannot be used for 
contouring or even in filling to form in cavities that have 
lost one or more of the surrounding walls: for in this man- 
ner of filling the principle of wedging the gold between 
the surrounding walls is depended upon to retain the gold. 
For this purpose only foil is used, and its lamina must ex- 
tend from the floor to the surface of the cavity. Either the 
form of the rope or cylinders may be used. In this form 
of filling the gold is not annealed. With our present ideas 
of preparing cavities only occlusal and buccal or labial 
cavities that have complete and good surrounding walls 
would be suitable for non-cohesive gold work. The forms 
in which we now prepare these are as suitable for non- 
cohesive as for cohesive gold, only that nd convenience 
points for starting the filling are required for non-cohesive 
gold. 

In filling an occlusal cavity in a molar with non-co- 
hesive gold cylinders we would prepare these so that the 
length of the cylinder- should be a little greater than the 
depth of the cavity. Some should be large and some small, 
the size of the larger ones depending upon the size of the 



FILLING WITH GOLD. 1 27 

cavity. Begin with the cylinder, which, as loosely rolled, 
would about fill the cavity full. Set this in the cavity with 
one of its ends standing upon the pulpal wall and the other 
protruding from its orifice. Now, with the side of a large 
plugger press the cylinder against the distal wall. Set 
another cylinder in in the same way and condense it 
against the first. Repeat this by adding cylinder after 
cylinder until the distal half or more of the cavity is filled. 
Then continue by condensing the cylinders against the 
mesial wall, and in turn the buccal and lingual walls, all 
the time using the lateral pressure with the side of the 
plugger point, not with its end. As the work progresses 
and the cavity room is narrowed, the cylinders introduced 
must be smaller and smaller. Finally, to obtain room for 
additional cylinders, a sharp point of a wedge form must 
be pressed to the floor of the cavity, and with a prying 
motion the gold is wedged against the cavity walls in 
every direction with great force. The space thus gained is 
again filled with small cylinders and the wedging repeated 
so long as it is possible to force in another cylinder. The 
small cylinders last introduced should be rolled very hard. 
When it is no longer possible to force another cylinder into 
the central portion of the cavity, efforts should be made 
at various points to force in the sharp, wedge-shaped point 
and any opening made filled with a small cylinder. When 
no more gold can be introduced the whole surface should 
be condensed as completely as possible with the end of a 
finely serrated plugger. Then the surplus gold should 
be trimmed partially and the condensation repeated. Then 
again, trim and condense, repeating this until the surface 
of the filling is brought to proper form, with its margins 
just flush with the cavity margins. Generally these fillings 
should be finished with the burnisher. 

Instead of the cylinders, ropes of foil may be used by 
carrying an end to the bottom of the cavity and folding in 
fold after fold, so that one end of the loop is on the floor 
of the cavity and the other protruding from the orifice. 
These loops are condensed against the walls teterally, and 
finally condensed by wedging, the same way as in filling 



128 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

with cylinders, filling the space gained by other loops. 
The filling is finished in a similar manner. 

In filling buccal or labial cavities with non-cohesive 
gold the steps of the procedure are practically the same as 
in filling occlusal cavities. However, the operation is 
generally rather more difficult in these, for the reason 
that the cavities are so generally of less depth in propor- 
tion to their breadth. The most convenient cavity to fill 
with non-cohesive gold is one in which the depth is nearly 
equal to the breadth. 

One who has become skilful with this manner of ma- 
nipulating non-cohesive gold can make gold fillings in 
cavities suited to this work in much less time than they 
can be made with cohesive gold. This plan of filling is 
often very desirable for first molars for children, and in 
various cases that come up in practice when it is important 
to shorten the time of the operation. 

These non-cohesive gold fillings do not stand attrition 
so well as cohesive gold fillings in positions where great 
wear comes upon them. They are, therefore, more suitable 
for buccal and labial cavities. If very well done, however, 
they do excellent service in occlusal cavities where the 
wear is not extraordinary. 

It is the general opinion of those who use much non- 
cohesive gold that water-tight margins are more certainly 
made with it than with cohesive gold. I am satisfied that 
this is correct. With the same care and skill more gold 
can be put into a cavity of a given size, using non-cohesive 
gold, than can be done with cohesive gold. 

The Application of Force in Filling with Cohesive Gold. 

In using cohesive gold in filling teeth all parts of the 
gold should be welded into one solid mass. This is accom- 
plished by using the gold in small masses and condensing 
each of these perfectly upon preceding masses with the 
end of the plugger point, by either hand pressure or the 
blows of the mallet. The use of hand pressure with suffi- 
cient force to accomplish this well, or to obtain the neces- 
sary degree of solidity, while it can readily be done, be- 
comes exceedingly tiresome to both the patient and the 



FILLING WITH GOLD. 1 29 

operator. For this reason mallet force has come into gen- 
eral use. The kind of mallet used for condensing the gold 
seems to be of much less importance than the particular 
manner of handling it, and this last must be stated as being 
a personal equation; that is to say, one person will accom- 
plish a given condensation of gold with much less incon- 
venience to the patient than another can do, and yet, the 
differences in the application of force are not such as permit 
of analysis and a determination of the precise differences 
in manipulation. 

Of the different plans of applying mallet force the 
hand mallet used by an assistant is by far the best, as it 
will produce the desired result with the least wear and 
tear to both patient and operator. The next best, but much 
inferior, method is by the use of the automatic mallet. Of 
these instruments there are a variety in the market of 
almost equal merit. The poorest method practiced is the 
use of the hand mallet by the operator himself. In this use 
of the mallet he cannot handle either the plugger or the 
mallet properly, and the usual result is great wear and tear 
upon both patient and operator, and generally much im- 
perfect work in condensing the gold, especially in its 
adaptation to margins. 

In order to condense gold well, and with the least pain 
to the patient, the mallet force should be combined with a 
certain degree of hand pressure. The plugger should be 
placed firmly in position with such force as to bring the 
looser portions of gold well together, and to force the tooth 
into a stable position in which the fibers of the peridental 
membrane are rendered tense, and then the blow from 
the mallet follows on the instant this is done. Experience 
has, I think, sufficiently shown that the best results are 
obtained by this method. This is in a good degree copied 
with the automatic mallets. 

The sliding of the plugger point over the surface of the 
gold while blows are being rapidly applied is very much 
more painful to the patient if the same results in condensa- 
tion are accomplished. A number of machines for this 
kind of malleting have been devised that are very con- 
venient in use, and yet they seem not to be much used, 
9 



I30 THE TECHNICAL PROCEDURES IX FILLING TEETH. 

evidently for the reasons I have assigned. It is perfectly 
practicable, however, to make good gold fillings by any 
one of these plans of using mallet force. The main ques- 
tions here are as to ease and rapidity of manipulation in the 
first instance, and, in the second, as to comparative ease of 
obtaining good results. 

In most fillings hand pressure should be used in the 
condensation of some particular parts to which mallet force 
is inapplicable. Mallet force can be applied successfully 
only in a direct line with the shaft of the instrument. In 
all cases in which it becomes necessary to apply force in 
lateral directions to the shaft of the instrument, hand pres- 
sure must be used, unless reverse pluggers can be substi- 
tuted. This can be done in the more difficult positions in 
lower molars and bicuspids by judicious study of the ca- 
pability of reverse pluggers. The filling of the incisal an- 
chorage in incisor cavities requires almost uniformly the 
use of hand pressure. 

The manner in which we now prepare cavities for filling 
reduces the necessity for the use of hand pressure more 
than ever before, because of the very free access obtained. 
Convenience in placing the filling material should always 
be held strictly in view in the preparation of a cavity. 

The Relation of the Size of Plugger Points to the Appli- 
cation of Force. 

A correct appreciation of relation of the size of the con- 
densing area of the plugger point to the force used is of 
first importance in filling teeth with cohesive gold. The 
force that can be applied is limited by the capability of the 
peridental membrane to resist, and the possibilities of the 
use of more or less force will vary with the strength and 
endurance of the membrane. People who have very strong 
peridental membranes and are accustomed to using their 
teeth very vigorously in chewing food, will' bear much 
heavier blows of the mallet than those who have weaker 
peridental membranes and habitually use their teeth more 
delicately. All of this must be considered in filling opera- 
tions and the force used limited accordingly. A point of 
no less importance is the requirements as to solidity and 



FILLING WITH GOLD. I3I 

strength of fillings for different persons. Persons with 
strong peridental membranes who rise their teeth vigor- 
ously require the strongest possible fillings. Persons who 
have weak peridental membranes and who habitually use 
their teeth feebly will not require the same solidity and 
strength in the fillings in order that they may stand. In 
either case, however, the adaptation of the gold to the mar- 
gins should be the same, and in all cases a density that will 
be moisture-tight is absolutely required. 

Because a patient can bear heavy blows of the mallet 
is no excuse for using a plugger of large impacting area, 
for the reason that such persons require very dense fillings. 

For condensing the main portions of a cohesive gold 
filling the impacting area of the plugger should never be 
more than one square millimeter, and generally plugger 
points of one-half to seven-tenths millimeter area should be 
used. The area of a plugger point is practically fhe square 
of its diameter. That is, a point one millimeter in diameter 
has an area four times as great as one half a millimeter in 
diameter. Five-tenths multiplied by five-tenths gives twen- 
ty-five as the area, while ten-tenths multiplied by ten-tenths 
gives one hundred, or four times as much. This being true r 
a reduction of the size of the plugger point below one mil- 
limeter increases the condensing power of the impact in 
proportion to the square of the reduced area, and increas- 
ing the size of the point above one millimeter diminishes 
the condensing power of the impact in proportion to the 
square of the increased area. Twenty-five pounds impact 
or pressure on a point one-half a millimeter in diameter is 
equal in condensing power to one hundred pounds upon 
a plugger point one millimeter in diameter. Therefore, to 
make solid fillings small condensing points must be used. 

We must not, however, use points that are so small 
that they will penetrate the gold and chop it instead of 
condensing it. Therefore we should not use heavy blows 
with very small plugger points. For some special places 
about margins, or packing in delicate grooves, a smaller 
point used with lighter force is useful. And occasionally 
a larger area than one millimeter in the form of a foot may 
be useful in packing over certain cavo-surface angles. 



132 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

Forms of plugger points. — The form of the impacting 
area or points of plugging instruments may be round, 
square, parallelograms, or what is known as the foot forms. 
All of these have their uses in special localities. For the 
general work of building cohesive gold either the round, 
square or parallelogram forms may be used. The foot 
forms are not suited to general building of gold, but are 
useful for condensing over certain cavo-surface angles and 
for after condensation, especially where it is necessary to 
reach into the interproximate space, or at other narrow 
points requiring a short crook of the plugger point. The 
parallelograms, or narrow flat points, are especially useful 
in condensing gold against the surrounding walls of cavi- 
ties when the direction of force must be nearly or quite 
parallel with the cavity wall, for the reason that they tend 
strongly to wedge the gold between the wall and the con- 
densed gold and perfect the adaptation to the wall. For 
this purpose the flat side of the plugger point is placed par- 
allel with the wall. 

The point or impacting area of the plugger may be 
smooth (smooth plugger), or serrated (serrated plugger). 
Gold fillings may be made with either, but for general use 
the judgment of the profession seems to be decidedly in 
favor of the serrated point. The principal object of the 
serrations is to prevent the point from slipping or sliding 
on the gold, and they should be just sufficient to do this 
effectively. Long, sharp serrations should not be used, be- 
cause they chop into the gold. Very fine, short serrations 
are much the best. Great care should be taken to keep 
plugger points in good order. 

Forms of the shanks of pluggers. — As we now prepare 
cavities with broad, free access, no great variety. of crooks 
and turns in the shanks are necessary. In the instruments 
for general use a slight bend in the shank is desirable in 
order that the shaft may be just a little out of the line of 
vision. A perfectly straight plugger is a little awkward 
for that reason. This curve should be from three to five 
centigrades. For special purposes we need some special 
forms of shank. Especially in filling upon the gingival 
walls of proximate cavities in the bicuspids and molars, 



FILLING WITH GOLD. 133 

a straight or nearly straight plugger would necessarily 
bring the angle of force almost perpendicular to the plane 
of the wall. In order that a more desirable angle of force 
may be had, a contra-angled shank is provided that will 
reach over the proximating tooth and permit an inclina- 
tion of about twelve centigrades of the angle of force to- 
ward this wall. In your sets there is a pair of these in par- 
allelogram forms of impacting area in which the width of 
blade is in opposite directions to the plane of the curves. of 
the shank. 

For filling the incisal anchorages of incisor cavities an 
angle of twenty-five centigrades (a right-angled plugger) 
is provided which is used entirely by hand pressure. This 
instrument, though used only for this one purpose, is a 
necessity to every outfit. These are. with the exception of 
the foot pluggers, the only curves of shanks required, and 
are quite sufficient for ordinary filling operations. 

In addition to these reverse pluggers of several pat- 
terns are advised, though not positively required of stu- 
dents, for use in some especially difficult positions. These 
are occasionally needful for certain positions in filling 
lower molars and bicuspids, especially for packing against 
buccal walls in teeth that have a strong lingual inclination. 

List of Pluggers Required. 

Both the trade number and the formula of each are 
given. * 

University No. 4, 5x10-3-3 ) Face rounded on dimension 

University No. 5, 10x5-3-3 ) 10; serrated. 

University No. 7, 6x4-5-5 j 

University No. 9, 6x12-6-10 { Contra-angled ; face rounded 

University No. 10, 12x6-6-10 ) on dimension 12 ; serrated. 

University No. 14, 5-2-23. 

No. 7, 5-10-3 \ 

No. 8, 7-10-3 V Round. 

No. 9, 10-10-3 ) 

*Note. — The first two terms of the formula with the X between (5 X 10) gives the 
size of the face of the plugger in tenths millimeters. If the face or point is round, only- 
one figure is used, which gives the diameter. The next figure gives the length of the 
point from the curve to its working end or face, in millimeters. The last figure gives the 
angle of the point with the shaft, in centigrades. 



University No. 6, 4x6-5-^ 

Tj ace flat; serrated. 



134 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

Xo. 2> 22 - 4*4 Bayonet; serrated. 

No. 393. 5x20. Angle of face 20: serrated. 

Xo. 408 5x20-5-15 I FoQt 
\ arney Ao. 5. 5x15-3-0 j 

1 Special Holding Instrument. 

1 Weston's Plugging Assistant. 

1 Automatic Plugger. 

Starting cohesive gold fillings. — In treating this sub- 
ject I will suppose that the cavity has been prepared as 
has been directed in the article on cavity preparation, 
and that the convenience points have been arranged for 
the beginning of the filling. Begin the filling in the most 
convenient angle of the cavity. In occlusal cavities this 
will usually be at some point along the pulpo-distal angle. 
In proximate cavities it will usually be the linguo-axio- 
gingival angle. It buccal cavities it will usually be the 
axio-disto-gingivai angle. In labial cavities it may be 
either the axio-gingivo-mesial or the axio-gingivo-distal 
angle, etc. 

Select a plugger point that will easily go into all parts 
of the convenience point with which to condense the first 
piece of gold, and have the holding instrument or the as- 
sistant plugger ready in the left hand. Select a piece of 
gold rope, cylinder or block, that seems rather large for 
the convenience point, and see to it carefully that it is well 
annealed. Convey it to the point with the annealing in- 
strument and catch it with the assistant plugger : hold it 
so while the annealing instrument is exchanged for the 
plugger selected, and with the two bunch the gold care- 
fully into the angle and catch it with the assistant plug- 
ger in such a way that the condensing instrument will 
have free access to the convenience point. Now. con- 
dense the gold into the angle by a few quick blows of the 
mallet, beginning in the central portion and drawing the 
outlying parts of the gold into the angle with the subse- 
quent blows. If the convenience point has been correctly 
formed this first piece will seldom need to be held after- 
ward, but sometimes a second and a third piece should be 
added while still holding the gold with the assistant plug- 
ger. In case the operator is using a hand mallet with his 



FILLING WITH GOLD. 135 

own hand this first condensation must be done by hand 
pressure. The first piece of gold should always be suffi- 
cient in quantity so that the plugger point will not come 
in contact with the dentin. The plugger point should never 
punch through the gold. Remember that if the bottom of 
your convenience point is round, as made with a round 
bur, this first piece of gold will roll, but if the bottom is 
well squared, as made with an inverted cone bur, this first 
piece of gold will remain firm. 

Next proceed to build up a mass of gold upon the first 
piece and extend this along one of the axial or pulpal 
angles to the second convenience point and unite the two. 
When this has been done the lodgment of the gold should 
be so secure that there will be no further fear of movement- 
and the body of the filling may be built upon this foun- 
dation. 

If the case is an occlusal cavity the building should at 
first be about equally upon the pulpal and distal walls, 
forming a triangular mass filling the disto-pulpal line angle 
and extending to the buccal and lingual walls. Later, after 
the anchorage has been made still more secure by some 
building across and across against the lingual and buccal 
walls, the building should proceed more rapidly upon the 
pulpal wall until this is covered and the gold brought 
securely into all of the pulpal line angles. 

In no case should there be any attempt to spread a 
thin layer of gold on the pulpal wall, or any other wail, 
of a cavity and condense it in a thin sheet. Any such 
attempt insures a failure of perfect adaptation to the wall 
of the cavity. Always secure a thick mass of gold along 
a line angle and build out on the wall gradually, keeping 
the thickened mass close to the margin of the building as 
it progresses over the wall that will keep the margin from 
curling away from the wall as it is condensed. 

The angle toward the plane of the wall at which the 
condensing force is applied is very important in making 
perfect adaptation. 

The direction of force should never be perpendicular 
to the plane of the wall that is being covered. Whenever 
possible the angle of force should be inclined as much as 



I36 THE TECHXICAL PROCEDURES IX FILLING TEETH. 

twelve centigrades from the perpendicular to the plane 
of the wall. In adapting gold to the surrounding walls 
in an occlusal cavity the direction of force should be in- 
clined toward the wall, if possible, as much as six centi- 
grades. It is quite possible, however, by using the wedg- 
ing principle, to secure good adaptation if the angle of 
force is parallel with the wall, but it is more difficult. 

The Wedging Principle. 

The stepping of the plugger should always be from, 
the central part of the mass of gold toward the walls, and 
the last condensation of each individual piece of gold added 
should be along the wall being covered. 

This rule is practically universal to filling with cohe- 
sive gold, except when condensing pieces laid upon central 
parts of the filling, no portion of which is condensed 
against a wall of the cavity. When the stepping of the 
instrument is toward the wall, finishing the condensation 
against the wall, the last of the gold is wedged between 
the wall and that last condensed, thus securing perfect 
adaptation to the wall. If. on the other hand, the condens- 
ation is begun at the wall, the tendency is to pull the gold 
away from the wall in moving from it in the condensation 
of the remaining portions, and to make imperfect adap- 
tation. 

In condensing each piece of gold added the stepping of 
the plugger point should be in a regular order, moving only 
the width of the condensing point at each step, condens- 
ing every portion of the gold. Regular lines of movement 
or stepping should be formed generally parallel with the 
wall that is to be approached, finishing along the wall. 
Such an order of work, pursued with regularity, secures 
speed in operating, and accuracy of adaptation of the gold 
to all parts of the cavity walls and margins. 

In the approach to and covering margins, great care 
should be had not to step the instrument onto the cavo- 
surface angle of the cavity. If this is done the cavo-sur- 
face angle of the enamel will be chipped and rendered im- 
perfect. As the margin is approached the gold should be 
laid over the cavo-surface angle in sufficient quantity to 



FILLING WITH GOLD. 137 

admit of malleting directly upon it, without danger of the 
plugger point punching through it and making contact 
with the enamel. This requires that the gold be built com- 
pletely over the margin at every point before the filling is 
regarded as completed. 

In finishing the building of the gold to form there 
should always be an excess to allow for sufficient trim- 
ming to remove all instrument pits and marks. It re- 
quires much care and good judgment to always have suf- 
ficient gold for a good finish, and not have a wasteful sur 
plus. 

The Gingival Wall in Proximate Cavities 

The management of the gingival wall in proximate cav- 
ities, especially in the bicuspids and molars, has always 
been the great stumbling-block in filling operations. It 
is confessedly the most difficult point at which to secure 
perfect adaptation of gold, or, indeed, any other filling 
material. In part, this difficulty has been from imperfect 
preparation of this wall, but the real difficulty in securing 
adaptation lies in the fact that the tendency is to apply 
the condensing force in a line perpendicular to the plane 
of that wall. To make perfect adaptation it is necessary 
that the angle of force be inclined as much as twelve cen- 
tigrades to the plane of the wall. 

In mesial cavities in bicuspids and molars this is easily 
accomplished by using the contra-angled pluggers which 
are made for this especial purpose (formula 6x12-6-10 and 
12x6-6-10). These instruments will reach over the prox- 
imating tooth and give the correct angle of force. The 
filling is begun in the convenience points, preferably with 
pluggers 5-10-3, or 7-10-3, round, and these are connected 
along the axio-gingival angle, as has been described. Then 
the building proceeds with the contra-angled pluggers 
about equally upon the axial wall and the gingival wall, 
creeping slowly over the gingival wall until its cavo- 
surface is reached and has been built over ; always 
keeping a thick margin of gold to build against 
while covering the wall and cavo-surface angle. During 
this building the plane of the surface of gold being built 



I38 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

should be inclined about twelve centigrades toward the 
long axis of the tooth, one margin of this plane being upon 
the gingival wall, and the opposite margin against the 
axial wall in a direction toward the occlusal surface in 
the central fossa, if a molar, and in a similar direction if a 
bicuspid. 

"When the gingival wall and its cavo-surface angle has 
been fully covered, then the building may be more rapid 
in the proximate portion, and the plane of the gold be 
brought parallel with the horizontal plane of the tooth. 
The mesial portion of the rilling is then extended to the 
mesial to make the contact with the proximating tooth. 
The rest of the filling is done according to rules previously 
given. 

In distal cavities in bicuspids and molars it is more 
difficult to obtain the best angle of force, and often the 
building must proceed differently. The angle of force 
inclined from the distal toward the mesial can not gen- 
erally be obtained, and it is necessary to substitute an 
inclination from the buccal toward the lingual. In the 
beginning, build a thick mass of gold in the axio-linguo- 
gingival angle, and gradually extend it out to the cavo- 
surface angle of the cavity at that point: then continue the 
building, keeping the plane of the surface of gold being 
built sloping occluso-gingivally from lingual to buccal. 
gradually covering the gingival wall and its cavo-surface 
angle, until the bucco-gingival angle is reached. Then 
wedge the gold into the bucco-gingival angle, between the 
gold already built and the buccal wall. After this is 
accomplished the building will proceed without especial 
difficulty. In accomplishing this the greatest difficulties 
will be found in lower bicuspids that have a distal and 
lingual inclination, and occasionally in lower molars that 
have a strong lingual inclination. In these the reverse 
pluggers are a necessity to easy and safe work. With 
these the procedure is the same as in mesial cavities, except 
that the order is reversed, as the left hand is the reverse 
of the right. Begin in the axio-bucco-gingival angle and 
work along the axio-gingival angle to the lingual, and gen- 
erally fill the axio-linguo-gingival convenience point with 



FILLING WITH GOLD. I39 

a direct plugger. After this is accomplished the building 
is not difficult. In making these fillings entirely with 
direct pluggers, hand pressure lateral to the direction of 
the shaft of the instrument is often necessary in starting 
the filling, and in building over the gingival cavo-surface 
angle, and also in much of the building against the buccal 
wall. 

In proximate cavities in the incisors and mesial sur- 
faces of the cuspids, no great difficulty will be found in 
gaining the proper angle of force in building over the 
gingival wall and its cavo-surface angle. These, like all 
other gingival walls and margins, should be covered only 
after having secured a mass of gold in the axio-gingival 
line angle, and then keeping the plane of the surface of 
gold being built sloped at an angle of about twelve centi- 
grades to the long axis of the tooth until the gingival wail 
and its cavo-surface angle are covered. 

Combination of Non-Cohesive and Cohesive Gold in 
Proximate Cavities in the Bicuspids and flolars. 

Combinations of non-cohesive and cohesive gold may 
be used effectively in many positions in filling teeth, but 
I attach great importance to it only in the gingival por- 
tion of proximate cavities in the bicuspids and molars. 
The best cohesive gold workers fail, when they do fail, 
oftenest at this point. And so difficult is it to make per- 
fect adaptation of cohesive gold to this wall that my 
observation teaches me that our very best men fail in ten 
per cent of their cases. A much larger per cent of success 
can be obtained by the combination of non-cohesive foil, 
with a saving of both time and labor. This is sufficient 
reason why I should urge this plan of filling. It is not, 
however, an easy matter to learn this method. It will not 
be gained without careful study and effort in practice. 

This combination consists of laying a large flat cylinder 
or mat of non-cohesive foil on the gingival wall and then 
beginning upon this to build cohesive gold. 

The beginning and continuation of the building with 
cohesive gold is the same in every respect as if the non- 
cohesive gold had not been used, except that it will be 



I4O THE TECHNICAL PROCEDURES IN FILLING TEETH. 

necessary to continue the use of the assistant plugger for 
a longer time before the mass is perfectly secure in its 
position. 

The flat cylinder or mat is made by first folding a sheet 
foil, or such part of a sheet as may be required, to the right 
width, and then rolling the ribbon formed upon a flat steel 
instrument of suitable width. The length of the cylinder 
is controlled by the width of the ribbon, and the breadth is 
controlled by the width of the flat instrument. The 
length should be such that when placed flat upon the gin- 
gival wall with one end against the axial wall the other 
end protrudes over the gingival cavo-surface angle of the 
cavity. The breadth should be such that it will extend 
fully from the buccal wall to the lingual wall and require 
some crowding to make it lay flat. Simply lay this in 
position and begin building upon it, practically as has been 
described for beginning with all cohesive gold. 

Instead of this flat cylinder or mat, ordinary round 
cylinders may be used by laying the first in the linguo- 
gingival angle, a second in the bucco-gingival angle, and 
crowding a third between the two. Or two cylinders may 
be used that have breadth enough to fill the space from 
buccal to lingual. Do not condense the non-cohesive gold 
before beginning with the cohesive. Merely adjust it in 
position with gentle pressure, and then condense it by 
building cohesive gold upon it. Then proceed as in all 
cohesive gold work, except that after the filling is other- 
wise finished the gingival portion should be very thor- 
oughly condensed from the surface. 

The reason that non-cohesive gold is safer in this posi- 
tion is that there is less disposition to curl from the mar- 
gin, and if there is any disposition to curl from the margin 
it is easy to make it tight by this after-condensation, 
because if not tight it moves readily under the blows of 
the mallet, while cohesive gold does not. Generally a con- 
siderable quantity of non-cohesive gold may be used in 
this way and greatly reduce the labor of making the filling. 

This plan of filling is especially adapted to proximate 
cavities in the bicuspids and molars. These fillings, as 
we prepare the cavities, are not anchored in the proximate 



FILLING WITH GOLD. I4I 

portion of the cavity, but in the step cut in the occlusal 
portion of the tooth. The filling- is supported against the 
force of mastication upon the broad, flat gingival wall as 
a seat, and when non-cohesive gold is laid upon this in 
the manner indicated and condensed by packing cohesive 
gold over it, it has all the supporting strength of the com- 
plete cohesive gold filling. 

This plan of using non-cohesive gold is not so well 
adapted to proximate cavities in the incisors and cuspids, 
for in these we have not the opportunity to make strong 
occlusal step anchorages, but must depend upon the 
gingival wall and its angles in part for the strength of the 
anchorage. To use non-cohesive gold upon the gingival 
wall would materially diminish the strength of this 
anchorage. The use of non-cohesive gold upon the gingi- 
val wall of proximate cavities in the incisors is not so much 
needed, for the reason that they are in much plainer view 
during the progress of building the filling. 

Strength of the Bite. 

In the consideration of the strength required in fillings, 
the strength of the bite, or the power with which the 
teeth may be closed upon food, is a matter of first impor- 
tance. This is to be considered with great care by every 
operator, both in general and in relation to each individual 
operation. The strength required in fillings is very much 
greater than was formerly supposed. It has been but a 
few years since we began to know definitely of the 
strength of the bite or of the strength actually required of 
fillings. I believe the first paper that brought this prom- 
inently before the profession was one which I presented to 
the Illinois State Dental Society in May, 1893. Follow- 
ing that, two instruments were presented for measuring 
the strength of the bite at the meeting of the World's 
Dental Congress in Chicago, later in the year of 1893, and 
very considerable interest was at once manifested in this 
subject, which has led rapidly to Considerable changes in 
the preparation of cavities and to a radically new study of 
the strength of filling materials. These instruments were 
presented, one by the late J. J. R. Patrick, of Belleville, 



I42 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

Illinois, and one by Dr. George Dennis, of Chicago. The 
instrument we are now using is a modification of the 
instrument presented by Doctor Dennis. It was immedi- 
ately found that the actual strength of the human bite was 
very much greater than had been supposed, and that the 
strength of fillings had been insufficient, and this was the 
cause of the rapid failure of many fillings, particularly 
proximate fillings. In order that the instrument should 
well represent the strength of the bite, the surface upon 
which the biting is done should be spread over the crowns 
of at least two molar teeth, but as it is the force of the 
bite is generally expended upon a single cusp of an upper 
tooth and a single cusp of a lower tooth, which does not 
give sufficient space to properly present the full power 
with which the jaws may be closed upon food. The 
strength of the teeth is found to be ample ; one can not 
break a tooth with the power of the muscles of the jaw, 
unless the biting is done on steel or some other very hard 
substance. In biting upon steel, or other substance equally 
hard, the area of tooth substance presented to the steel 
will be very small indeed, and by hard biting the enamel 
may be fractured. But when the substance bitten upon 
is soft, as a piece of hard rubber, the tooth will sink into -t 
a little and spread the area of stress more upon the surface 
of the tooth. On hard rubber or the softer metals I have 
never known a person to check the enamel of a tooth in 
biting with all the power of the muscles. Therefore, the 
teeth are abundantly strong, unless we happen to catch 
them on a bit of gravel or a large bit of sand, or some- 
thing of that kind that is extremely hard. Half a dozen 
students who tried the force of their bite on the Gnatho- 
dynamometer* during one of my lectures last year, reg- 
istered respectively, 155, 190, 250, 220, 225 and 150 pounds. 
This represents very fairly the usual amount, and the 
variations in the stress persons with fairly good teeth, and 
of ordinary habits in their use, can exert. A few will exert 
a greater stress, as much as 275 or 300 pounds. Many 
people who use their teeth delicately will stop at 100 
pounds or less. 

* An instrument for measuring the force with which the jaws may be closed. 



STRENGTH OF. THE BITE. I43 

Often persons have registered 100, 130, and, occa- 
sionally, 200 pounds and over on the central incisors. 
Generally persons biting upon the instrument stop because 
it hurts the peridental membranes; they do not register 
the full power of the muscles of the jaws. A few tell me 
they have exerted the full power of the muscles without 
pain, and in these cases I suppose the full power of the 
muscles is registered. 

In chewing food we use, as a rule, very much more 
stress than is actually required to crush the food. By try- 
ing the crushing strength required, with the phago-dyna- 
mometerf we may find the crushing power required for 
the various foods. Filberts that school children are in 
the habit of crushing with their teeth give a register of 
from 100 to 150 pounds, occasionally more. In chewing 
meats much difference in the required stress is shown, 
good beefsteak requires from forty to sixty pounds, tough 
beefsteak from sixty to eighty pounds, occasionally more. 
Mutton chops usually require from thirty to forty pounds, 
pork chops (loin) twenty to twenty-five pounds, broiled 
ham from forty to sixty pounds, etc. If any one in chew- 
ing a piece of beefsteak will notice it he will hear a crack- 
ling sound just at the time the fiber of the flesh is break- 
ing up. We can notice that also in the phago-dynamom- 
eter, and just at the time that the fiber is breaking up we 
find that the meat crushes out from between the teeth and 
the teeth pass through it and come together. Most per- 
sons in chewing meats of any kind crush their teeth 
through it at a dash. A person who chews feebly will not 
do this. A person who is chewing with artificial teeth 
generally can not. A person who can use forty pounds 
pressure upon artificial teeth is doing very Well, and such 
persons will often find their beefsteak very tough ; but a 
person who can crush down 200 pounds can eat any beef- 
steak. In the ordinary chewing of beef or flesh, great 
force is not required, we may say, and yet, if we catch upon 
a bone, or, in game, upon a shot, we will get a terrible jolt 
upon the teeth, for we actually use much more than the 
necessary force. That is as likely to come upon fillings as 

t An instrument for measuring the crushing force necessary in chewing different arti- 
cles of food. 



144 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

upon any other part of the tooth, and, of course, will give 
the strength of the filling a sore trial. In chewing meats 
the motion is directly up and down : we do not use the 
lateral movement in chewing meats. In this we copy the 
motions of the carnivorous animals. The carnivorous 
animals have their jaws hinged so that they have but the 
up-and-down motion used in crushing. We crush our 
meats ; we do not grind them. In chewing bread, or any 
of the grains — the cereal foods — we do use the lateral 
motion ; we grind them ; Ave can not crush them. The 
more we crush upon bread the more we pack it between 
the cusps of the teeth. A little lateral motion will cause 
it to go to pieces quite readily, but we can not crush even 
a comparatively soft bread crust with all the force that 
we can put upon it ; it will simply pack into the sulci 
between the cusps of the teeth and remain there. This 
is shown very readily with the phago-dynamometer. If I 
put a piece of comparatively soft crust in the instrument 
and put on a pressure of 60, 80 or 100 pounds it is simply 
pack'ed between the teeth and has not been cut through 
at all. A little lateral stress will grind it. Patients used 
to come to me saying that they had broken the cusp off 
of a bicuspid, for instance, "just biting a piece of soft 
bread." Sometimes I thought it was a kind of a joke, and 
sometimes I felt that it was absolute dishonesty ; I did 
not know the facts until I began to try the artificial chew- 
ing of food. Then I found that there was a substantial 
reason for it, for in taking a piece of bread crust between 
the teeth, without having it wet, we may crush with all 
the force of the muscles and simply pack it between the 
cusps of the teeth and bring to bear a powerful splitting 
force, calculated to throw off a cusp from a tooth. In 
this way we lose the cusps of a good many teeth, and 
teeth are broken from plates, crowns are broken, bridges 
are broken, "just in biting a piece of soft bread crust." 
In these several ways very powerful stress is brought upon 
fillings, and cavities must be cut with the view of giving 
great strength to the fillings and of maintaining the 
strength of the teeth. 

It is for this reason that cavities are prepared in certain 



STRENGTH OF THE BITE. I45 

ways. In occlusal cavities, as they are formed by decay, 
the puipal wall will usually be rounded — will be circular. 
This would be the form of the cavity after the removal 
of the decay. Now, this gives an opportunity for the roll- 
ing of fillings ; the filling is not as easily placed ; it is more 
difficult to make a good filling in such a cavity and the 
filling is more easily moved by the force of mastication. 
It might stand for a considerable time in chewing beef- 
steak, if it had no bones in it, no bits of gravel, or in chew- 
ing game, if there were no shot that would come upon a 
particular portion of a filling and cause it to roll. But if 
the seat is cut flat, then the filling is supported in such a 
way that it is not disposed to roll. Again, a still more 
important point — when in a mesio-occluso-distal cavity in 
a molar or a bicuspid, with the pulp removed so that the 
tooth is open through from mesial to distal, the breadth 
of the pulp chamber is considerable ; and perhaps there 
has also been decay that has further weakened the den- 
tinal walls. If the filling is finished in the normal form 
of the occlusal surface, leaving the inclines of the cusps 
toward the central area of the tooth standing, the food 
catches between these inclines of the cusps upon the 
buccal and upon the lingual. In this case the patient 
crushes down upon a bread crust ; it packs between these 
inclines of the cusps and great force is brought upon 
them, and the lingual wall or the buccal well is broken 
away, "just biting a piece of bread crust." For this rea- 
son it is necessary to take great care in the preparation of 
all such cavities. Never leave the central incline of a cusp 
under such conditions. No matter how good it may be, 
no matter how perfect the enamel may be, no matter if it 
is supported by dentin immediately beneath, never leave 
it. It may be strong toward the occlusal, but more toward 
the gingival it is weak, and it is that weak portion that 
we need to protect. In all of those cases cut to the crest 
of the cusp, at least so that when food is packed between 
the cusps the stress will come entirely upon the filling; 
let the filling material take this strain instead of the cusp 
of the tooth. This will also remove the possibility of 

catching a shot or a piece of bone upon the cusp of the 
10 



I46 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

tooth and throwing it off. It is that which is caught upon 
the slope toward the central portion of the tooth that 
crushes it off, not that which is caught upon the slope 
toward the axial surface of the tooth. This is more essen- 
tial in the bicuspids than it is in the molars, because they 
are less strong. In an ordinary mesio-disto-occlusal cav- 
ity, where the pulp is still retained, the inclines of the cusps 
may be left with perfect safety. All the strength of the 
muscles will not break it. But when the length of the 
walls is increased by extending the cavity to the floor of 
the pulp-chamber the case is entirely different. The bicus- 
pids have sharper inclines than the molars, and food 
wedged into their sulci has a greater splitting force, and 
in these, with a mesio-occluso-distal cavity, and the pulp 
removed, it is necessary to protect the cusps in every way 
possible. 

In building out central incisors that have lost an angle 
there is only about half the stress to contend with as upon 
the molars ; and yet, in some instances there is as much 
as 200 pounds brought upon them. It is not uncommon 
for persons to take a bread crust between the teeth and 
put stress upon it, perhaps the full strength of the muscles 
of the jaws, and then tear it off with the hand, putting an 
additional force upon it. Now, that we have to build 
against, in building up these angles. We must prepare 
for this in the anchorage of the fillings and depend upon 
the strength of the gold when they are built. In this case 
it is necessary that we have the welding property of the 
gold perfect in every part; any carelessness in the anneal- 
ing of the gold will tell in the breakage of fillings in incisal 
angles. A little portion imperfectly annealed will make a 
fault; a little imperfection in the malleting will make a 
fault, either of which will extend over a portion of the 
area and cause a break. In the preparation of gold for such 
building we should generally resort to annealing upon a 
tray, allowing the gold to remain hot for a considerable 
time in order that every particle may be well annealed. 
And. then pack the gold with a plugger point with a small 
condensing area, and go over every part of it with great 
care and use enough force. 



FINISHING FILLINGS. I47 

The force required in making fillings, and the strength 
required of fillings, will depend largely upon the strength 
of the peridental membranes. If the peridental mem- 
branes are not strong the patient will not use the teeth 
very vigorously, and fillings of less strength will answer. 
But be careful not to under-estimate that. If the pulp has. 
been removed from a tooth and it is still somewhat sore 
it may be very difficult to use sufficient force, and one may 
be deceived ; for when it is well the patient may put great 
force upon it. One should study each individual case as 
to the strength of the peridental membranes, the probable 
habits of the patient in chewing food, and build the filling 
accordingly. A person whose peridental membranes are 
strong, who, from the appearance of the teeth, you would 
suppose used much force in masticating food, particularly 
in cases where teeth are worn, you may expect uses great 
force in the mastification of food, and you must build fill- 
ings accordingly, and see that every portion of gold is well 
annealed and malleted well home. 

A careful study of persons in regard to the force they 
use in biting seems to me almost essential in the practice 
of dentistry. I know it is difficult to do that without being 
equipped with the proper instruments for this study. I 
wish everyone could be equipped with the instruments 
for taking the bite of patients. Many patients will become 
interested in it and it would afford a fund of information 
that would be of great benefit. 

Finishing Fillings. 

Except in proximate cavities in the presence of a proxi- 
mating tooth, trimming fillings to form and finishing 
presents very little difficulty, and requires no special 
preparation for the finishing before the filling is intro- 
duced. In these it is necessary to the proper finishing that 
the teeth be separated, either before the filling is begun, 
or at some time during the building of it, to allow room 
for finishing the surface to the correct form. This separat- 
ing has been described. 

Before any finishing is begun, the cavity must be 
filled more than full at every part to allow for sufficient 



I48 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

trimming to remove all instrument marks, leaving a sur- 
face condensed to an even, perfect hardness. 

In occlusal, buccal, labial and lingual cavities, the first 
trimming may be done with the engine, using fine-cut fin- 
ishing burs, or corundum stones, as may be most con- 
venient, or in some positions the trimming may be done 
with the finishing files. Rotary instruments used in the 
dental engine should be passed over the surface of the gold 
in some regular order, being careful not to cut too deeply 
in some parts, or cutting down irregularly. In occlusal 
cavities, when the bulk of the trimming has been done 
in this way, overlaps will remain in the grooves and irreg- 
ularities of the surface. These are best removed 'with the 
discoid excavator, or spoons 20-9-12. These instrumenrs 
should be very sharp. 

In buccal and labial cavities the finishing of the gingival 
margin is the difficult point. Generally no attempt should 
be made to cut these fully down to the enamel margin with 
the bur or stone, but after the first part of the cutting has 
been done, the gingival margin should be trimmed w T ith the 
files or with the finishing knives. In some positions this 
will be done easiest with the knives ; in others it will be 
done easiest with the files. Generally the knives should do 
the last part of the trimming, for the reason that the sharp 
edge (and it must be very sharp to be of use) will catch 
under the least overlap, find the exact enamel margin, and 
cut to it with certainty. In using the finishing knives no 
effort should be made to cut away a thick mass at a single 
stroke, but rather so catch it as to remove thin shavings 
and pare down the gold little by little. Used in this way 
they will, in positions suited to their use, cut faster than 
any other instrument used for this purpose. Great care 
should be taken not to overtrim the gingival margin, cut- 
ting away part of the thin enamel, or all of it, leaving a 
depression. This is very liable to be done by the careless 
use of the stone, and forms a depression in which debris 
will lodge, setting up fermentation which will insure the 
recurrence of decay at that point. This error is a very 
common one. All parts of the margin of the filling should 
be trimmed exactly to the cavity margins. This should be 



FINISHING FILLINGS. I49 

so perfect that a sharp edge or a sharp point will slide from 
the enamel onto the filling, or from the filling onto the 
enamel, without the least catch or interference with the 
perfectly smooth movement. All parts of the sur- 
face of the filling should harmonize with the sur- 
face of the tooth ; or, in other words, should 
reproduce the tooth form with accuracy. Then the 
whole surface should be evenly polished. This is 
best done by using a rubber disk of triangular form with a 
sharp outer edge armed with pulverized pumice, rotating 
rapidly in the engine. Or, on axial surface fillings, the sand- 
paper disk may often be used to advantage. When all 
instrument marks have been removed with this it may be 
followed by a leather disk and pumice, which at the last is 
carefully run dry. This will give a brilliant surface. In 
using the engine great care must be taken not to develop 
too much heat, as this is likely to cause severe pain, and 
may do permanent injury to the pulp of the tooth by setting 
up hyperemia. 

A hard steel burnisher should not be used on cohesive 
gold fillings, for, if used with force enough to be of value, 
there is danger of checking the enamel margins, and for the 
reason that there is no necessity for its use if the surface of 
the filling has been well condensed. 

Finishing proximate fillings. — The teeth having been 
separated to give room, and the filling built out sufficiently 
to allow of its being finished to the original mesio-distal 
breadth of the tooth, the gold will have been packed very 
solidly against the proximating tooth. The first thing is 
to cut through between this tooth and the filling with a 
Kceber saw, held in the Wilson or Sibley frame. This cut 
should be close against the proximating tooth, removing 
as little gold as possible. Now, take a thread saw (made 
by grinding from the back of a Koeber saw on an ordinary 
corundum wheel until its width is reduced one-half), place 
it in the frame with the teeth toward the back, and pass 
this between the filling and the proximating tooth and work 
it under the gingival margin of the filling against the neck 
of the filled tooth and, sawing toward the occlusal, cut 
away the overlap of gold. Afterward the saw may be 



I50 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

turned first one way and then the other, and cut away the 
overlap well around to the buccal and to the lingual in case 
of very broad fillings. Then the saws have done their 
full duty. In cutting away the surplus with the saw espe- 
cial care should be had not to cut too much toward the 
occlusal, and thus cut away the contact point. Now, with 
the finishing knives, begin at the gingival and, cutting fine 
shavings (the knives must be sharp), remove any remain- 
ing overlap first and shave the proximate surface and the 
gingival portion of the embrasures to the required form. 
When the hand has become trained to the use of these 
knives, and they are kept sharp, this part of the work is 
quickly done and well done. 

The buccal and lingual embrasures are then to be 
trimmed to form, and the contact which has been left flat 
with the saw must be rounded. This part of the work is 
best done with the file-cut finishing files. 

The blades of these files must be sharp to do this work 
well. When they have become dulled they are easily 
sharpened with slips of Arkansas stone, made for this pur- 
pose. Each blade is to be carefully ground sharp by draw- 
ing the stone back and forth against it. Generally, oil 
should be used on the stone. When the edge of the stone 
has become dulled or gaped it may be sharpened by whet- 
ting on fine emery paper laid flat on a table. Generally 
these files may be used with the thumb and palm grasp, 
and the flat sides applied to the gold in the embrasures, 
and with short, strong strokes almost parallel with the 
long axis of the tooth, the excess of gold is quickly re- 
moved. As the margins of the blades of these files are 
thin and sharp they can pass well into the embrasure to- 
ward the contact point, rounding the surface just up to that 
point without cutting over it. This is done first on the 
buccal and then upon the lingual, and the contact point 
sharply rounded, and the embrasures, lingual and buccal, 
rounded to the proper form. 

In the interproximate space proper, when the files must 
cut from lingual to buccal between the teeth, the rounded 
v/orking surface files must be used to give the filling the 
proper form and leave the contact point with its proper ful- 



FINISHING FILLINGS. 151 

ness. With these one can work up close to the contact 
point without danger of cutting it away. The file should 
not be used on the contact point, but finally this should be 
rounded and smoothed with the fine grit finishing tape. 

Obtaining this marble-like roundness of the contact 
point is the critical requirement in finishing prxoimate 
fillings. If the surface is cut flat the contact will grasp and 
hold food between the teeth and cause annoyance and pain, 
and cause injury to the gum septum by forcing the confined 
food against it. Neglect of this precaution has caused the 
loss of thousands of otherwise good fillings, and the teeth 
themselves, either by causing a recurrence of decay or by 
inducing disease of the peridental membrane. 

The occlusal surface, if the case be a molar or bicuspid, 
is to be trimmed and finished as described for occlusal fill- 
ings, after which corrections are made in the occlusal third 
of the proximate surface, and the whole filling polished. 

Polishing of proximate surface fillings should be done 
partly with tape and partly with disks in the engine. Tapes 
should be used for polishing the gingival two-thirds of the 
surface, or all of that portion of the filling to the gingival of 
the contact point, having especial care not to cut away the 
contact point. Narrow strips should be used. The em- 
brasures, buccal and lingual, should be polished with disks, 
usually not more than five-eighths of an inch in diameter, 
in the engine. The disks should never be allowed to pass 
the point of contact, as they would quickly ruin the filling 
by cutting away the contact point, but should be confined to 
the embrasures and the buccal and lingual margins. When 
this has been completed satisfactorily, a very fine tape may 
be passed a few times over the contact point, rounding it 
and completing the polish. 

The importance of the form of fillings will be considered 
more fully when the causes of caries and the conditions of 
its occurrence have been presented. 

Selection of Cases for Porcelain Inlays. 

Porcelain inlay work must, as yet, be regarded as in 
its infancy. It has not yet reached its full development as 
to the best plans of prosecuting the work, nor has its power 



152 THE TECHNICAL PROCEDURES IX FILLING TEETH. 

of controlling recurrence of decay been fully determined. 
While this remains true, anything that may be said regard- 
ing the selection of cases for inlay work must be regarded 
as tentative, and subject to such modification as future de- 
velopments may require. The indications at the present 
time seem to be that its power to control caries will be 
much less than well-planned and well-made gold fillings. 
Neither is it capable of the same quality and kind of 
anchorage, and in most instances is less securely placed. 
The cement used in securing it in position is often very un- 
reliable, and even when it holds well it is subject to waste 
about its margins, which gives rise to roughness and lodg- 
ment of debris. The enamel margins of the cavity cannot 
be prepared in the best form to stand, and both these and 
the margins of the inlay are liable to become chipped and 
roughened, all of which tend to invite a recurrence of decay. 
This can, to some extent, be modified by placing the cavity 
margins upon the axial angles of the teeth, where they will 
be best cleaned by the excursions of food in chewing. 
Eut whatever its usefulness may be in the future, time will 
be required for its determination. Therefore, for the pres- 
ent great care should be exercised in the selection of cases 
for its use. 

The first and principal objection to gold filling is its 
unsightly appearance in large fillings in the front teeth, par- 
ticularly of young adults who are much in social life and 
those who are much before the public as singers or speak- 
ers. Notwithstanding this, gold fillings have done excel- 
lent service in the past in saving teeth that were badly de- 
cayed, and we may rest assured that our communities will 
give up little of the more substantial benefits derived from 
gold for the more esthetic appearance offered by the new 
material. It must prove itself the equal of gold in saving 
teeth from decay or it will speedily be consigned to a few 
special uses, or to use in a few selected classes of cases. 

For these reasons, its trial should, for the most part, be 
confined to : 

First. Those cases, occurring in young adults, most 
prominently demanding esthetic consideration. 



FINISHING FILLINGS. 1 53 

Second. Those cases in which the apparent immunity 
to decay is such as to give the greatest promise of perma- 
nence. 

Third. Cases in which gold filling is contra-indicated 
on account of injury to the peridental membranes through 
disease that renders the malleting required for the con- 
densation of gold unusually painful or positively injurious. 

Fourth. Cases in the back teeth in which there is great 
loss of tooth substance in which crowns or very large amal- 
gam fillings have formerly been used, but in which porce- 
lain may be anchored. 

In the first of these classes we should confine our selec- 
tion to such cavities as would show so much gold when 
filled with that material as to materially injure the facial 
expression of the individual. This may again be defined as 
any showing of gold that will call prominently the atten- 
tion of associates, or in public singers and speakers the at- 
tention of an audience. Many persons will prefer the more 
esthetic appearance of neatly made inlays for the time, 
running the risk of a greater mutilation of the teeth by de- 
cay in the future. For the most part these will be young 
adults or -those not long past maturity. 

Of the second class of cases, those practically immune, 
there are many, especially among those of mature age, if 
we know how to select them, in which porcelain inlays 
may be made with much certainty of success so far as 
danger of recurrence of decay is concerned. With these, 
the permanent retention of the inlay is the principal 
question. 

In the third class, the recurrence of decay is not to be ex- 
pected, as the general condition of body in which disease of 
the peridental membranes occurs and in which decay of the 
teeth occurs, rarely occur together. Therefore, as the 
weakened membranes should not be tortured by the mallet- 
ing of gold, the inlay should be chosen on all proper occa- 
sions. 

Of the fourth class, chance cases are continually occur- 
ring in any considerable practice, usually where fillings 
placed long previous have broken away, and in which very 
much of the crown of the tooth is gone, making a large 



154 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

filling necessary, in which gold is practically prohibited be- 
cause of the necessary malleting, and yet anchorage for an 
inlay may be had. In many of these cases a well-con- 
structed inlay may be used, instead of a large amalgam 
filling or a crown. This inlay, if it be a back tooth, may be 
formed of gold often to advantage simply by fusing gold 
into the formed matrix, instead of filling it with porcelain. 
In this case the margins of the cavity may be prepared as 
for a gold filling and thus be made more secure than with 
the porcelain inlay. 

Whether or not a porcelain inlay will give a better 
appearance than a gold filling in any particular case will 
depend upon the comparative neatness of the adaptation to 
esthetic conditions in the two cases. A gold filling in view 
always declares itself as such without question, and is a 
decided blemish if not neatly done. When well done and 
in good form, it gives an expression of neatness and good 
taste that does much to obliterate the very unesthetic sen- 
sation of "a patch." On the other hand, a porcelain inlay 
that is ever so little out of form, or off color, so that it is 
noticed as something wrong, is a blemish undefined and 
questioned by every observer. 

Nothing violates esthetic principles more radically than 
this condition of question. Therefore, the porcelain inlay, 
to be successful from the esthetic standpoint, must be 
unseen. It must be practically perfect work, or the well 
made gold filling would be better from every point of view. 
It is for this reason very largely that the inlay is not to be 
used in teeth from which the pulp has been removed. If 
the inlay be adjusted ever so nicely and the tooth becomes 
opaque later, the inlay will be off color and becomes a 
blemish that will be worse than the showing of a gold fill- 
ing. When I have myself removed the pulp from a tooth 
and filled the root under favorable conditions, I should 
not hesitate to place a porcelain inlay, for I should not 
expect an amount of discoloration that would be noticeable. 
If, however, the tooth had come to me with a dead and 
decomposing pulp, or with abscess, I should expect discol- 
oration that would prohibit the use of porcelain. 



FINISHING FILLINGS. 155 

The Inlay. 

The porcelain inlay having been determined upon and 
the cavity having been prepared to receive it, the steps in 
its production are divided into three distinct parts : The 
production of the matrix in which to form the inlay ; form- 
ing and baking the inlay, and setting the inlay in the cavity. 

The matrix. 

The matrix may be formed by any one of several 
methods, depending partly on the porcelain used and partly 
upon the previous experience of the operator. As to the 
porcelain, it is prepared in the form of a powder, called 
bodies, the ingredients being mixed in different propor- 
tions by the different makers, producing varieties. These 
different varieties fuse at different temperatures. By 
common consent, the products from these are divided into 
high fusing porcelains and low fusing porcelains. All of 
those that fuse at a lower temperature than pure gold are 
called low fusing bodies, while those that fuse at a higher 
temperature than pure gold are called high fusing bodies. 
The choice of low fusing or of high fusing bodies or porce- 
lains for the particular case controls the choice of the 
material for the matrix. With the low fusing body, gold 
may be used ; with the high fusing body, platinum must be 
used. Gold foil of the weight or number of 60 is much 
easier to burnish or swedge to the cavity walls than plati- 
num of similar weight, because of the greater pliability of 
the gold. 

In respect to the choice of high or low fusing bodies, 
there is a curious division of sentiment existing in this 
country. In the West, the high fusing bodies are almost 
universally used, while in the East the low fusing bodies 
are as universally chosen. If one has learned to use the 
platinum matrix, he should have no special difficulty in 
using gold later. As this is regarded as one of the difficult 
steps in the process, it should first be practiced on extracted 
teeth until one has obtained some facility in handling the 
material. Cavities on the axial surfaces of the teeth being 
the easier of management, these should be selectee! first. 
The object to be attained is to fit the thin platinum per- 



I56 THE TECHNICAL PROCEDURES IX FILLING TEETH. 

fectly to the walls of the cavity in every part and to the 
surface of the tooth immediately adjacent. This is intended 
to give a perfect copy of the cavity, and in this cavity 
formed in platinum the porcelain inlay is formed and baked. 
This must be so perfectly done that the inlay thus molded 
will fit the cavity in every part when the platinum has 
been stripped off. This may be done by burnishing the 
platinum to the walls of the cavity in the tooth itself, or be- 
taking an impression of the cavity and forming a model 
upon which the matrix is swedged. Most operators seem 
to prefer the former method. 

The platinum prepared for this purpose by the dealers 
is reduced to 1-1,000 of an inch in thickness, and some is 
now prepared one-half this thickness. 

A scrap of this platinum is cut that will not only cover 
the cavity well, but will also so extend beyond the cavity 
margins as to cover some portion of the tooth surface sur- 
rounding the cavity, giving room for some "drawing in" 
that will occur in forming the platinum to the cavity walls. 
This, having been freshly annealed at a white heat, is laid 
with its central part over the cavity, and while held in this 
position, this central portion is pressed down into the cavity 
with a little ball of cotton held in the pliers. This should 
be done gently and cautiously to prevent tearing the plati- 
num by too great a strain in some particular part. In doing 
this, press the cotton ball about in different directions, 
allowing the edges of the platinum to tip up some to facili- 
tate the sliding of the platinum down into the cavity, but 
not so much as .to form folds in the material that will be 
difficult to smooth out later. When some considerable 
change in the form of the platinum has been produced, it 
should be removed from the cavity and again annealed at a 
white heat to restore its former softness. In forming plat- 
inum, this annealing is very important, and should be 
repeated at frequent intervals during the progress of the 
work. The platinum is stiffened at every bend that is 
made and its liability to tear greatly increased. The 
annealing brings it back to its former state of softness, and 
if the annealing is repeated sufficiently often, it may be 
worked into almost any form without tearing. 



FINISHING FILLINGS. 157 

After the annealing it is to be returned to the cavity 
in exactly the same position it previously occupied and the 
work with the ball of cotton repeated, pressing the plati- 
num more and more closely to the cavity walls at each 
annealing until the cavity can be forced full of cotton over 
the matrix. Then the margins lying on the surface of the 
tooth should be smoothed down to the surface of the tooth 
with a steel burnisher used lightly, being careful to smooth 
out all tendency to the formation of folds. 

Now an examination will show that while generally the 
platinum is fitted to the cavity walls, it has not been forced 
perfectly into the angles. It should again be annealed and 
returned to the cavity, and while held in position it should 
be gradually forced into all angles with a smooth steel bur- 
nisher. Burnishers for this work are provided by the 
dealers in a suitable variety of forms. The burnishing may 
be facilitated by cutting a small band from rubber dam and 
placing this over the tooth so as to cover the matrix and 
hold it firmly in position. A small hole should have been 
cut in this rubber and placed immediately over the cavity 
to work through. This rubber Will prevent any tipping 
of the matrix while burnishing. When this is apparently 
complete, reanneal and return the ■ matrix to the cavity, 
and when it is well settled into position, touch it at differ- 
ent points with the point of the burnisher and look care- 
fully for any springing or tilting. If there is any, the. part 
where this occurs is not perfectly fitted and must be bur- 
nished down. 

Before this burnishing is finally completed, that portion 
overlapping the surface of the tooth should be trimmed 
fairly close and yet left sufficiently long to show very 
plainly the cavity margins and form of the surrounding 
surface ; for this is the guide to the fullness of the inlay. 
It is often well to leave one convenient point a little long 
to facilitate handling with the pliers. When the finished 
matrix is finally removed from the cavity, it should be done 
with the greatest care not to bend it in any of its parts. 
To this end, it should be very carefully teased out until 
well loosened from its bed, when it may be carefully lifted 
away with the pliers. The pliers for this purpose should 



I5& THE TECHNICAL PROCEDURES IN FILLING TEETH. 

have a locking device, so that when once the inlay is taken 
up it is permanently held. The matrix is now ready to 
receive the porcelain body for baking. 

There are a number of processes in which the impres- 
sions of the cavities are taken and the inlays swedged over 
these as models, or in which a reverse of the impression is 
made and the inlay formed in that. 

An impression of the cavity may be taken in modeling 
compound or hard wax by coating the walls of the cavity 
with vaselin to prevent sticking, and may be removed in 
very perfect condition if allowed to first become fully hard. 
Either of these, when reinforced with plaster, may be used 
to swedge upon by the water bag or similar sw'edging 
devices of which there are many forms in the market. Or 
they may be used for making reverse dies by carefully 
building over them with a good amalgam and allowing this 
to become hard. For this purpose the impression is usually 
set in a form with plaster of Paris, which gives a cup in 
which to pack the amalgam. The impression may also be 
taken in cement either by oiling the cavity, or better by 
forming the stiffening cement into a globule and rolling it 
in pulverized soapstone to prevent its sticking. This makes 
a very hard impression which, when reinforced with plas- 
ter, serves well to swedge over with the water bag swedg- 
ing device. Nearly every man who uses these devices 
introduces some particular methods of his own to facilitate 
the work, so that there are almost as many processes as 
workers with these devices, each one doing fairly well with 
his particular plan of work which he has learned to handle 
with accuracy. With time, some one of these plans, or one 
yet to be developed, will prove itself best and become gen- 
erally used. 

There is a serious objection to the oiling of the cavity 
for the reason that it is impossible by any washing with 
ether or alcohol to get the walls as clean as they would 
have been if no oil had been used, and to that extent the 
hold of the cement upon the cavity walls will be impaired. 

flaking the Inlay. 

In making the inlay, the great esthetic point is to get 
the proper translucence and color. I place translucence 



FINISHING FILLINGS. 1 59 

first because it is of even greater importance, if possible, 
than the exact color. Extracted teeth quickly lose this trans- 
lucence and become more uniformly grayish white. There- 
fore, no amount of work on extracted teeth will give a cer- 
tain guide to obtaining the proper translucence in the 
mouth. But this work will give facility in handling the 
material and in obtaining the desired shades, and should 
be carefully practiced before undertaking work in the 
mouth. To facilitate the production of the varying shades 
of color of the natural teeth dealers have prepared the 
bodies in a sufficient variety of shades. The tooth operated 
upon and those in the immediate neighborhood should be 
carefully cleaned as a. first step, and the translucence and 
color carefully examined, compared with specimens of porce- 
lain made from the bodies at the operator's command, and 
the color and gradations for translucence determined. This 
should be done prior to the completion of the preparation of 
the cavity and before the rubber dam is put on. It is not 
the appearance of the dried tooth that one is to copy in 
the porcelain, but the appearance of the clean, moist tooth. 
A tooth well dried with the rubber, dam on becomes opaque. 
One of the principal points in obtaining the proper trans- 
lucence is to use the more opaque color first, bake or biscuit 
this separately, then add the more translucent colors in 
one or more layers, finishing with the enamel body, or in. 
those preparations in which no enamel body is provided 
with that shade which is more nearly transparent. This 
plan of building up the inlay is found to be of great impor- 
tance in obtaining esthetic effects, and will do much to hide 
the effects of the opaque cement, which must be used later 
to fix the inlay in position. Often a prepared inlay will 
appear as perfection itself when laid in the cavity without 
cement, but when cemented in place will look very badly 
because the opaque cement shows through the porcelain 
and completely changes its tone of color and translucence. 
In this regard very much may be done by a judicious 
arrangement of the cavity walls and margins, especially by 
such an arrangement as will place the edge of the cement 
line toward the observer. I do not think that any fixed 
rules can yet be given in words that will give much valua- 



l60 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

ble information in this building-up process in making porce- 
lain inlays. It must be obtained by practice. 

The powdered body is first mixed with water to form a 
creamy paste of even consistence, using an orangewood 
stick in preference to a steel spatula for the reason that 
the smallest particle of iron will cause discoloration of the 
fused porcelain. Then a portion of the body chosen for the 
first layer is flowed into the bottom of the matrix, shaken 
down, and the superfluous water taken up with a little 
pledget of soft absorbent cotton or blotting paper. For 
this work cotton is not so likely to leave filaments in the 
mass as punk and should be preferred. Indeed, every part 
of this work must be done in the most cleanly manner 
possible, as any fiber or moat that will carbonize in baking 
is liable to destroy the good appearance of the inlay. The 
shaking-down process is very important in the matter of 
gaining solid, strong porcelain, and in preventing shrinkage 
in baking. Its object is to obtain the greatest possible 
solidity of the body. It is done by holding the pliers, with 
the inlay, in the hand and drawing a roughened instrument, 
such as the edge of a coarse cut eighth round file, across an 
angle of the blade of the pliers. This gives to the body in 
the matrix a very quick, short vibration which settles it 
quickly to the bottom, while the water comes to the top 
and can be obsorbed away. This should be repeated until 
no more water will come to the surface. In this way 
enough of the body is placed for the first layer and then 
baked. This first baking need not come quite to a full fuse, 
but should be very near to it for the best results. The 
matrix with this portion of the inlay may now be returned 
to the cavity to see if any bending has occurred, and cor- 
rections made if necessary. After this, other layers of 
more translucent body are added as desired for the particu- 
lar case, filling the matrix nearly full, but not quite, and 
baked in one or several layers as may seem most desirable. 
At this point especially, it is desirable to return the 
matrix and inlay to the cavity and carefully reburnish the 
margins of the matrix to the cavity margins to correct any 
possible "drawing in" of the inlay margins by the shrink- 
age of the porcelain in baking, and to observe very partic- 



FINISHING FILLINGS. l6l 

ularly the fullness desired in the finished piece. When it is 
determined no further additions of the principal body is 
required, the inlay must be finished by the addition of the 
enamel body, or the final shade when no enamel body is 
used, in which the rounding out to the proper fullness 
should be looked to with especial care. With the 
same care, also, it should be seen that the margins 
are filled exactly flush at every point, and also that 
there is no overplus about the margins that will 
form thin edges that will break away in setting and 
leave a roughness of the margins. In the final work a 
magnifying glass should be used. The margins of the 
inlay should be sharp and definite angles at every point. 
When this has been accomplished, the whole is to be 
returned to the furnace and baked, and in this bake a full 
fuse to a glaze of the surface should be obtained, taking 
great care not to heat too much ; for this is likely to burn 
out the color and the translucence, leaving the inlay an 
opaque gray unsuited to the case. Facility in baking can 
be acquired only by careful practice. The eye and the 
fingers must be trained to the work by doing it, as in any 
other technical process that requires skill. 

Furnaces for Inlay Work. 

There are a number of furnaces on the market for inlay 
work. Generally a small furnace made especially for this 
work, or at least one made for very small pieces, should 
be used. It may be electric or some one of the devices for 
the use of gasoline or gas. The electric oven is the best, 
the neatest and most compact. With it there is no percep- 
tible heat, noise or dirt, and it may be used beside the chair. 
But it requires the electric connections and rheostat for the 
control of the heat. A considerable variety of forms of 
these are on the market. Any arrangement by which suffi- 
cient heat can be produced with reasonable regularity of 
control will do. It may be done over the flame of a good 
Bunsen gas burner or in the flame of a gasoline blast by 
having a small muffle of platinum to protect the porcelain 
from the direct blast. 

11 



l62 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

Setting the Inlay. 

When the inlay has been completed, the platinum 
matrix is stripped off. Generally this may be pulled away 
with the pliers. Occasionally, however, this gives trouble. 
If the last traces of it cannot be removed by picking it 
away, it may readily be removed by placing it in aqua regia 
and, with the aid of a little heat, dissolving away the 
remainder. 

The inlay should now be placed in the cavity and 
closely examined to see that the fit, color and all are satis- 
factory. The method of handling the inlay deserves some 
attention. It may be taken up in a pair of light tweezers 
and placed in the cavity, or it may be stuck to the end of 
some instrument with a little sticky wax. Whatever the 
arrangement, the handling should be done very lightly and 
accurately, for there is considerable danger of chipping 
either the sharp margins of the inlay or the equally sharp 
margins of the cavity. The inlay is to be secured in the 
cavity by cementing with oxyphosphate cement. 

In selecting the cement for this purpose, the following 
points should be observed : 

The cement should be as impenetrable to moisture as 
possible. 

The adhesive property should be the strongest possible. 

It should be very finely ground. 

These points are discussed under the head of "Cements" 
and need only mention here. 

As the inlay is held in position by the adhesion of the 
cement, this may be increased by etching all of that por- 
tion of its surface that is to lay in contact with the walls 
of the cavity. This roughens the surface slightly so that 
the cement has a better hold. This is readily done by cov- 
ering with wax to protect that which is to be the exposed 
surface of the inlay when set, and then exposing the rest 
of its surface to the action of hydrofluoric acid for five 
minutes ; then washing off with ammonia, followed by 
water. The wax may be dissolved away by chloroform. 
Some operators cut grooves in the inlay, but that seems 
unnecessary. Scratching the dentin walls of the cavity 



FINISHING FILLINGS. 163 

with a fine pointed instrument may also serve to strengthen 
the hold of the cement. 

When all arrangements for handling the inlay in setting 
have been made, the cement should be mixed to a creamy 
consistence and spatulated until it is very smooth and 
evenly mixed. Then a very small amount should be taken 
on the point of a small spatula and placed in the cavity and 
so worked about, either with this or a smaller instrument, 
that it is seen to take to every part of the cavity walls and 
displace all air bubbles. The cavity should be filled suffi- 
ciently to insure that in the introduction of the inlay no air 
will be included between it and the cement at any point. 

The inlay should then be placed in the cavity, displacing 
the superfluous cement by pressure. This is best done by 
a light zigzag or very short up and down movement, going 
continually deeper into the cavity until the inlay has set- 
tled firmly into position. The adhesion of the cement to 
both the inlay and the cavity wall will be much increased 
by this vibratory motion. Then a very considerable pres- 
sure should be made and some of the redundant cement 
removed from about the margins to see that the inlay has 
gone properly to place. This pressure should now be kept 
up for some minutes — the longer the better, or until the 
cement has firmly set. Generally it will be seen as this 
pressure is being kept up that more and more cement is 
gradually oozing from the margins, so that really the inlay 
is sinking into the cavity, thinning out the cement between 
it and the cavity walls. If the pressure is removed too 
quickly, and a margin closely watched with a hand magni- 
fier, it can usually be seen that the inlay rises just a little 
out from its bed ; hence, this sustained pressure is impor- 
tant. This pressure should not be with steel instruments, 
for these are too liable to chip the inlay, especially if any 
slip should occur. Some kind of wood point is perhaps 
best for this purpose. 

When the cement has become fully hard, the redundant 
cement should be removed, and the operation is complete. 
It should, however, be protected from moisture by keeping 
the rubber dam in place for half an hour longer, in order 
that the cement may become as hard as possible. 



164 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

Filling with Amalgam. 

I will preface the consideration of the manipulative pro- 
cedures in filling with amalgam by saying that every detail 
of the cavity preparation should be the same as for filling 
with gold, except that convenience points for starting the 
filling need not be made. Neither is it quite so explicitly 
required that convenience forms of the walls for access 
be so rigidly observed, though there should not be much 
difference. If possible, the anchorage should be stronger 
than for gold, and as amalgam is so much used for very 
badly decayed teeth, especially in bicuspids and molars 
from which the pulps have been removed, advantage 
should be taken of the pulp chamber to strengthen the 
anchorage. The pulp chamber should be filled solidly with 
amalgam to the pulpal orifice of the root canals when using 
it in pulpless teeth. With the amalgam we are using nowa- 
days the teeth will not be discolored if the filling is prop- 
erly made. The amalgam exposed upon the surface will 
discolor up to the margins, but the amalgam that is in con- 
tact with the walls of the cavity will not discolor, and con- 
sequently will not discolor the tooth. It is only when the 
amalgam filling leaks about the margins that the tooth is 
discolored by it, and as we can now use amalgams that do 
not shrink, discolorations of the teeth will occur only 
through imperfect manipulation. The fact that amalgams 
used in the past and until very recently would shrink, caus- 
ing leakage, is the reason why teeth filled with it have 
been so generally discolored. It is not easy, however, to 
make mechanically perfect amalgam fillings, and for one 
to succeed uniformly requires skill and the utmost care in 
every detail. 

Amalgam is admissible only in the bicuspids and 
molars. 

All cavities filled with amalgam must have continu- 
ous surrounding walls during the building of the rilling. 

We can not build up a corner of a tooth with amalgam 
and expect good adaptation to the walls, for the material is 
plastic, and, when pressed upon, the whole body of the fill- 
ing is liable to movement. To prevent this, complete sur- 
rounding walls are a necessity. Therefore, whenever .a 



FILLING WITH AMALGAM. 165 

cavity presents that has not four surrounding walls, the 
missing walls must be supplied by artificial walls. This is 
done by the application of the matrix. It is to be used in 
filling all proximate cavities, and in any others in which 
one wall is broken down. 

Placing the matrix. — When a proximate cavity is other- 
wise ready for filling with amalgam, a slip of thin metal 
plate (copper, brass, German silver or steel) is cut of 
sufficient width to extend from the occlusal surface of 
the tooth to near the gingival line, or far enough to fully 
cover the gingival margin of the cavity, and long enough 
to encircle about half the tooth. The rubber dam having 
been applied before the excavation of the cavity was com- 
pleted, this slip is passed between the teeth and roughly 
fitted to see that the width and length are right. Then at 
the corners to the gingival a little ear is turned with the 
pliers that will prevent a ligature from slipping of! to the 
gingival, when it is drawn tightly around the tooth. Also 
the cut ends of the metal should be so bent that the sharp 
angles will not cut the ligature. This is now passed 
between the teeth so as to cover the proximate portion of 
the cavity. Then a ligature is thrown two or three times 
around the tooth, including the matrix, tightly drawn and 
tied. This is often a difficult operation for the beginner, 
but after a little experience the manipulation comes easy 
enough in most cases. A few cases occur where the con- 
ditions are unfavorable and try one's wits, but these can be 
successfully done by a little effort. When this has been 
done the Perry separator is applied over the matrix, or in 
many cases the matrix may be held with the separator 
without the ligature. It is just as important to separate 
the teeth for amalgam fillings as for gold fillings, and on no 
account should this be neglected in any proximal fillings 
where there is an approximating tooth. After the prepara- 
tion is otherwise complete, a careful examination of the 
gingival margin of the cavity should be made to see that, 
the matrix is close at that point, and if it is not, it should be 
brought close, by inserting a small, soft wood wedge from 
the lingual side with just sufficient force to bring the 
matrix close. This is most likely to be needed in molars 
that have broad, flat, proximate surfaces. 



l66 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

Preparing the Amafgam. 

It is of great importance to obtain in the beginning the 
right proportions of alloy and mercury. This proportion 
will vary with the alloy used. Of the higher grades of alloy 
we are at present using, this proportion is very nearly equal 
parts by weight, but generally a slightly greater proportion 
of mercury is required, or about 52 per cent. This propor- 
tion should be carefully determined for the alloy used, 
and the proportions weighed for each mix. We think this 
of such importance in our infirmary work that we have this 
weighing done, and the proportions put in separate cap- 
sules. I have also found that to undertake to knead the 
alloy with too much mercury results in very imperfect 
kneading and makes a weak amalgam, while to knead with 
too little mercury also makes a very weak amalgam, and 
a mass that is too granular and stiff to work well. 

Kneading. 

The first of the kneading is done best in a wedgewood 
or ground-glass mortar. This should be continued until 
all of the fillings are incorporated with the mercury, when 
it should be turned into the palm of the hand and vigor- 
ously kneaded with the fingers. For this work the hand 
should be as dry as possible. This kneading should be 
continued until the mass is perfectly soft, plastic and free 
from granulation. If in the kneading the mass becomes too 
very soft there is too much mercury in the mix, and so 
soon as that is determined a portion of the mercury should 
be removed by squeezing the mass between the fingers and 
the kneading immediately continued, for if the mass is 
allowed to stand for even a few moments in this condition 
it is likely to become too stiff for rekneading. When suffi- 
ciently kneaded, the mass should not very readily break 
when rolled into a long roll in the palm of the hand. 
Everything should be in exact readiness to insert the filling 
and the packing immedaitely proceeded with, for if the 
alloy is just what it should be, the mass will begin to 
stiffen very quickly, and possibly become unfit to work 
before the packing is completed. 



FILLING WITH AMALGAM. 167 

Packing Amalgam Filling. 

The importance of the best form of instrument for pack- 
ing amalgam can hardly be overestimated. Until I had 
examined this over and over again, experimentally, under 
conditions which enabled me to determine results, I had 
no idea of the importance of the instrument forms for this 
purpose. The one thing needful in packing amalgam is to 
grasp the mass as a whole as nearly as possible, and com- 
press it into the cavity. The whole principle of making 
perfect work is contained in the one word, compression. 
Therefore, the cavity must be a simple one with complete 
surrounding walls, or must be converted into a simple 
cavity by supplying any missing walls with the matrix. 
Then the instrument point should be flat and as large as 
the cavity will conveniently admit, and, when practicable, 
its form should be such as to as nearly fit the cavity as 
possible. With it and the walls of the cavity the mass of 
amalgam should be grasped as perfectly as possible and 
powerfully compressed, so as to force the amalgam into 
all parts of the cavity. About all the force the hand is cap- 
able of should be brought upon it and maintained for an 
instant. Then more of the mass is added and again pres- 
sure applied. This should be done as rapidly as perfect 
work will admit, until the cavity is full and much more 
than full. Indeed, more of the mass should be added and 
compressed as long as compression of the mass in the cav- 
ity can be made by adding to the surface, for the time 
comes when the mass added simply spreads out over the 
cavity walls. If, during the packing, there are narrow 
parts of the cavity or irregularity of walls into which the 
larger instruments do not go well, a smaller instrument 
should be used to pack the amalgam into them. These 
should not be used with such force as to crush into the 
mass and chop it up, but only with such force as will com- 
press. When the cavity is full it should be allowed to rest 
undisturbed for a few minutes to give it time to stiffen a 
little before attempting to remove any of the surplus. 



1 68 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

Cautions. 

In filling with amalgam, it is imperative that a certain 
disposition of the mass to stiffen, or harden quickly under 
pressure, be obtained so that when the mass has once been 
compressed into the cavity, it will not readily move. In 
order that this may be obtained, the alloy must be so made 
and tempered that it will set quickly and yet give suffi- 
cient time for quick working of the prepared mass. Very 
much of this, however, depends upon the development of 
skill in kneading the mass to just the right consistence. 
This kneading should be done actively and quickly, keep- 
ing it in motion every instant from beginning to end. If 
allowed to lay still, it begins at once to stiffen, but may be 
kept soft a considerable time by active motion in kneading. 
In all cases the mass should become soft enough to take 
quickly and perfectly impressions of the markings of the 
corrugations of the skin on the palmer surfaces of the fin- 
gers (finger markings), and be tough enough to be rolled 
out into a long, slender roll in the palm of the hand and yet 
contain no excess of mercury that can readily be removed 
by squeezing between the fingers. This, when once com- 
pressed, should immediately become firm and brittle. In 
this condition a portion of the mass compressed into a 
cavity retains its position perfectly when more of the mass 
is compressed over it. This freedom from movement after 
the first compression in packing the filling is especially 
important in making watertight fillings. A soft mass that 
remains spongy under the packing instruments is always 
moving with every motion of the packing instruments, 
and when pressed against one wall of the cavity will draw 
away from another wall, or when pressed upon in the cen- 
ter will spread in every direction and then draw back when 
pressure is removed. With such a mass it is impossible 
to make a watertight filling with any certainty. Xo amal- 
gam that is slow in setting and works very soft in the cav- 
ity should be used in filling teeth. Independent of after 
shrinkage or expansion, good fillings cannot be made 
with it. 



FILLING WITH AMALGAM. 169 

Instruments. 

In the list of instruments there are three round points of 
different sizes from small to large for the more ordinary 
work, and then there are two pairs arranged with special 
reference to filling occluso-proximate cavities. One of each 
of these pairs will fit fairly well into the proximate por- 
tion of these cavities, and the other into the step. They 
grasp and compress the mass well in either of these posi- 
tions. All of them are serrated to prevent slipping and 
sliding. These instruments should be used in all amalgam 
work. 

Heretofore many dentists have used burnishers to pack 
amalgam fillings, thinking they could burnish amalgam 
securely to the walls of the cavity. This is a popular error. 
I once supposed I could do this, and could prove it by 
burnishing amalgam onto a toothbrush handle, causing 
it to stick so firmly that I could build a great mass upon 
it and the whole would cling very tightly. But on prying 
this off and examining the surface that stuck so w r ell with 
the microscope, I found it full of fine bubbles. In trying 
some of these in an aniline dye I found that these bub- 
bles became filled with the colored fluid. In trying this in 
cavities in teeth and breaking the tooth after the arnalgam 
was hard, I found the same thing occurred. Finally, I 
became convinced that the endeavor to make a perfect 
amalgam filling with a burnisher was a failure. The thing 
simply can not be done. The amalgam will flake up from 
the wall and the adaptation be imperfect. 

Finishing Amalgam Fillings. 

When the amalgam filling has stood a few moments to 
stiffen in some degree, the surface should be trimmed to 
form with a discoid or spoon excavator, if on an occlusal 
surface, and carefully burnished toward the walls, using a 
light pressure that will not be liable to move the mass as a 
whole. If upon an axial surface, as the buccal, it may very 
conveniently be trimmed with the finishing knives and all 
overlaps removed, and then carefully but lightly bur- 
nished. If an occluso-proximate filling, trim the occlusal 
portion before removing the separator, as this work will 



I/O THE TECHNICAL PROCEDURES IN FILLING TEETH. 

give a little more time for the mass to harden to prevent 
the filling being crushed by the teeth dropping together. 

When the separator is removed the matrix will be 
firmly held between the rilling and the proximating tooth. 
Any attempt to pull this out is liable to injure the filling. 
In this case straighten out the ends of the matrix to the 
lingual and to the buccal and reapply the separator with 
the matrix between the claws. Then tighten the sepa- 
rator sufficiently to loosen the matrix and remove it. 

Now, while the separator is in place, with the finishing 
knives trim the proximate surface to form and remove ail 
overlaps about the margins. Then burnish lightly, remove 
the separator and the rubber dam. Be careful to note the 
occlusion, and if a cusp of an opposing tooth strikes the 
filling, trim it down so that there may be no danger of 
injury to the filling from that cause. 

Trimming to form as described is very important, 
because it can be done at this time while the amalgam is 
still but partially hardened, with ease, and very quickly. 
If we wait until the amalgam is fully hard it is a tedious, 
difficult operation. 

The patient may now be dismissed for one, two or 
three days, as may be mutually convenient, or until the 
amalgam is fully hard. Then the whole filling must be pol- 
ished. This polishing is practically the same, is done with 
the same instruments as a gold filling, and must be done 
with the same care. In proximate fillings it is very often 
necessary to reapply the separator to properly finish the 
proximate surface and the contact point. 

The Cements. 

The cements at present available for use in filling oper- 
ations are the oxy-chloride of zinc and the oxy-phosphate 
of zinc. The composition of these you have already learned 
in the chemical laboratory. Formerly the oxy-chloride of 
zinc cement was much used, but since the introduction of 
the oxy-phosphate it has fallen into disuse on account of 
the very irritating qualities of its fluid portion. The phos- 
phate of zinc cement is very much less irritating and is 
generally preferred for this reason. The cements are 



THE CEMENTS. I7I 

received from the dealer in two separate bottles, the one 
containing the powdered oxide of zinc and the other the 
fluid. In use a small portion of the powder is placed upon 
a porcelain or glass slab, and a drop or two of fluid is 
placed beside it. The two are then drawn together and 
thoroughly mixed by rubbing them together with a spatula. 
This spatulation should be continued until a very smooth, 
creamy mass has been formed. The mixture of the oxy- 
phosphate should be much thicker and stiffer than the mix- 
ture of the oxy-chloride to obtain the best results with the 
respective cements. Indeed, the oxy-chloride may be 
mixed so thin and soft as almost to flow, and yet become 
very hard and firm ; while the oxy-phosphate, to produce 
the best mass, should be rather stiff, yet it may be quite 
plastic. 

As yet there has been very little careful examination of 
the physical properties of these cements. We do not know 
accurately the proportions of powder and fluid required to 
produce the best results. It is probable that these vary 
with the different makes of these cements, and also with 
the age, for the fluids seem to be inconstant in their proper- 
ties. It has been the constant habit of dentists to mix 
them without any rule, simply observing the plasticity of 
the mass produced, being governed entirely by the eye 
and the observation of the results. This must be regarded 
as a very inaccurate method of using this material, but so 
long as we are without more accurate knowledge of it than 
this gives, we can only follow it. Very recently some work 
has been done on the physical properties of the cements by 
Doctor Wedelstaedt of St. Paul, and by Doctor Ames of 
Chicago and others. In this work it has been shown that 
most of the cements are readily permeated by moisture, 
while some are not, and also that some of the cements will 
shrink badly while hardening. 

In mixing the oxy-phosphate it seems to be best to draw 
the powder into the fluid and incorporate it little by little 
until the required stiffness of the mass has been acquired. 
Just what this should be can not, in the absence of care- 
fully conducted experiments, be definitely stated. In prac- 
tice it is varied with the particular use to be made of the 



172 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

particular mix. If for filling and setting crowns, in which 
case great plasticity is required, the consistency of very 
thick cream is usually acquired, and this very thoroughly 
spatulated and used quickly, or before it has begun to 
stiffen. If for filling cavities in teeth, more of the powder 
is added and the mix made stiffer, and the spatulation con- 
tinued somewhat longer, so that the mass assumes a putty- 
like consistence. It seems to be the general notion that 
when mixed in this way a much stronger mass is formed. 
This idea is strongly supported by some recent physical 
experiments, yet these have not been in sufficient number, 
nor have they been sufficiently i^aried as to conditions to 
give certain working data. 

These cements are not impervious to moisture. Some 
experiments have recently been made as to the qualities of 
the cements with regard to exclusion of moisture, and it has 
been found that none of them is actually impermeable, 
while many of those on the market admit moisture readily. 
As yet, we do not know with any degree of certainty upon 
what these differences depend. They are, however, very 
important. Other things being equal, the cement that is 
nearest moisture-tight is the best for use. Any one may 
try cements by making experimental fillings and placing 
them for a day, or two or three, in a solution of aniline dye, 
and then breaking them open and observing the penetra- 
tion of the color into the mass of the material. Some of 
the cements will be penetrated through and through in a 
very short time, while others will resist for a longer time. 

It has also been determined that those that expand in 
setting are very readily penetrated by moisture, while 
those that shrink while hardening are less penetrated by 
moisture. Those that shrink most seem, thus far, the 
hardest and most impenetrable by moisture, and con- 
versely, the hard, impenetrable cements shrink badly. This 
shrinkage renders them useless in filling teeth. At present, 
therefore, we seem compelled to use the medium hard 
cements for filling operations and for the setting of crowns. 
In setting inlays where there is so thin a film of cement 
shrinkage may be less important, and their impenetrability 
to moisture renders their adhesive properties, which are so 
important in this work, much more permanent. 



THE CEMENTS. 173 

When made into fillings in teeth the cements do not 
resist perfectly the solvent action of the oral secretions. 

They are slowly dissolved, or waste away. They are, 
therefore, not very permanent fillings. In this regard 
great differences are observed. In a few cases cement fill- 
ings have done excellent service for many years, seem- 
ingly resisting the action of the oral secretions perfectly. 
In the majority of cases, however, they dissolve away within 
two or three years, and in many instances within a few 
months. We have not yet such a knowledge of the condi- 
tions of these variations as will enable us to control them, 
and must therefore regard cement fillings as temporary in 
their nature and qualities, expecting to renew them at fre- 
quent intervals. 

Use of the Cements. 

The cements are used for setting crowns and bridges, 
for temporary fillings, and for preserving for a time teeth 
that are very badly broken down, or in other conditions 
which seem to render the use of the metallic fillings unde- 
sirable at the time. They may also be used for temporary 
fillings in cases of very sensitive dentin for the purpose of 
allaying the extreme sensitiveness, which is generally found 
to disappear, in large part at least, within a few weeks or 
months. They may also be used for temporary fillings in 
cases of hyperemia of the dental pulp with marked advan- 
tage, for the reason that their conductivity of thermal 
impressions is less than that of the metals, though in this 
respect gutta-percha is much better than the cements ; also 
they may be used in capping exposed pulps. 

The cements are also much used for sealing treatments 
in pulp-chambers and root-canals. This last use of the 
cements is not good practice. They do not perfectly 
exclude moisture. Gutta-percha is much better for this 
purpose for the reasons, first, that gutta-percha is imper- 
meable to fluids, and moisture-tight fillings can be made 
with it ; second, gutta-percha is much more easily removed 
from the cavity in opening it for changes of the applica- 
tions. It is very painful to cut out a cement filling when 
the peridental membrane of the tooth is sore, while gutta- 



174 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

percha may be softened by heat and removed with very lit- 
tle pain. 

Filling with Cement. 

In filling cavities with cement the preparation should be 
well made, all of the walls being cleaned by perfectly 
removing all carious dentin to sound tooth structure, and 
the walls and margins trimmed smooth. Some degree of 
retention should also be given to the cavity form, but this 
is not so imperative as with metal fillings. 

The cavity should be perfectly dry at every part, for in 
this case we may expect that the cement will adhere 
strongly to the cavity walls and in part sustain the filling in 
position. The cement should be mixed with as much of the 
powder as will work into a plastic mass and spatulated 
vigorously until it has begun to stiffen, and, when at the 
consistence of putty, should be packed into the cavity in 
moderately small masses, using as much force as the con- 
sistence will allow, adding piece after piece, until all parts 
of the cavity are full and overfull. Then a few moments 
should be allowed for the cement to stiffen a little more, 
after which the filling is trimmed to form with the finishing 
knives. In this trimming the cement should be so stiff 
that the stickiness shall have disappeared, for it is only 
just at this time that it can be cut smoothly without drag- 
ging. After trimming it may be burnished lightly, and if 
necessary smoothed with polishing strips. 

After the filling is completed, if the softer or more pen- 
etrable cements have been used, it should be protected from 
moisture for some minutes, the longer the better, as the 
cement will become harder. It seems that when moisture 
is admitted early a part of the phosphoric acid is dissolved 
out of the cement, robbing it of a part that is necessary for 
the most complete hardening of the mass. If, however, the 
harder cements have been used the shrinkage will be much 
greater if the filling be kept dry. The admission of mois- 
ture soon after the cement begins to harden limits the 
shrinkage very materially, therefore moisture should be ad- 
mitted soon after the cement begins to stiffen enough for a 
good finish to be made. From what is now known it would 
seem that for setting inlays the hardest and most impene- 



GUTTA-PERCHA. 1 75 

trable cements should be used. With the very thin film 
remaining between the inlay and the walls of the cavity 
the shrinkage cannot be of much importance. The more 
important point is that the adhesive property of the cement 
which is depended upon to retain the inlay is lost if the 
cement is penetrated by moisture, at least in large degree. 
The cement which will retain this property longest is the 
best for this purpose. 

These general principles should be observed in all uses 
of cements. Softer masses must be used in setting crowns 
and some other operations requiring a plasticity approach- 
ing a fluid condition, but it should be remembered that this 
renders the cement less strong and more soluble, and is to 
be avoided whenever the conditions of the case in hand will 
allow. 

Gutta-percha. 

Gutta-percha is used for various purposes in connection 
with filling operations. The best form for this purpose is 
the ordinary base-plate gutta-percha. Besides this, how- 
ever, a multitude of makes for the purpose of filling teeth 
are found in the market. None of these is superior to the 
ordinary base-plate, and the greater number of them are 
very inferior. Many of them seem to be mixtures of gutta- 
percha and ; wax that soften very readily by heat. These 
are especially to be avoided. 

Gutta-percha is the best material we have for root fill- 
ing, for sealing dressings in root-canals, and for most of 
the temporary stoppings used in connection with treatment 
cases. Under certain conditions it is also an excellent 
material for more or less permanent fillings in cavities in 
the teeth. 

Filling with Gutta-percha. 

In filling cavities in teeth with gutta-percha the cavity 
should be prepared almost as for gold or amalgam, but 
generally convenience points for starting may be dispensed 
with. The cavity .should, however, be made as strongly 
retentive as possible. When otherwise ready for filling, 
every portion of the cavity walls should be moistened with 
eucalyptol or oil of cajuput. These oils take strongly to 



1^6 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

the cavity walls and also dissolve slightly the surface of 
the gutta-percha as it comes in contact with it. The oil 
then diffuses through the mass of the gutta-percha and is 
lost, apparently., leaving the gutta-percha adhering firmly 
to the cavity walls. Therefore, for this purpose the cavity- 
walls should only be moistened. Xo excess of the oil 
should be allowed to remain in the cavity, as the effect will 
be to soften the whole mass of the filling. 

Prepare the gutta-percha by gently warming it over the 
flame of the alcohol lamp, or upon a warm tray. Care- 
should be had not to heat the gutta-percha too hot. This 
will develop an inordinate stickiness of the mass, and it will 
not again become fully hard : the quality of the material is 
permanently injured. 

W nen it is made just plastic by heat, convey it to the 
cavity in small pieces and build the filling up from the most 
convenient angle or wall of the cavity piece by piece, stick- 
ing the warm pieces to the mass in the cavity with a con- 
siderable pressure, and condensing well against all walls 
and margins. In this work it is well, if possible, to add no 
more of the material than will just fill the cavity, having 
none to remove in trimming. If, however, a surplus has 
been added, warm a small flat burnisher sufficiently to 
quickly soften the gutta-percha upon contact, and with this 
cut away the surplus, and immediately condense and adjust 
the surface of the filling with a cold burnisher that has 
been laid ready. The finish should generally be made en- 
tirely with the burnisher, as we can not polish the surface 
of the filling by any of the usual means. By waiting until 
the filling is fully hard it may be trimmed with a sharp 
knife, but the edge must be very sharp to cut smoothly. 
This is the best instrument for removing overlaps and mak- 
ing a good finish of margins. 

Another plan of filling with gutta-percha that is useful 
in many cases, especially cavities of easy access, is to form 
a mass that will just fill the cavity and warm it only suf- 
ficiently to obtain the necessary plasticity, and insert the 
whole filling in one piece, condensing with a broad, cold 
instrument, afterward finish as before described. 

Much experience is required to handle gutta-percha 



EXPOSURE AND REMOVAL OF THE DENTAL PULP. \*JJ 

well, but when once the manipulation has been learned it is 
not difficult, and requires but little time. It should be the 
only material used for sealing in dressings, and for the 
temporary stoppings in connection with treatments. 

Gutta-percha is too soft for permanent fillings in any 
positions that are exposed to the stress or friction of masti- 
cation. In some cavities, where it will not be exposed to 
wear, it will do most excellent service. It is especially to 
be recommended for filling cavities in the buccal surfaces 
of the teeth of old people, especially those that are in large 
part in the cementum, and extend beneath the free margin 
of the gum. 

It is often useful as fillings in the temporary teeth for 
children. By renewing it from time to time these teeth 
may be made useful until removed in the shedding process. 
However, children often wear it out of cavities rapidly, 
and it needs to be very frequently renewed. 

Gutta-percha is also very useful in the treatment of 
sensitive dentin, and in cavities of teeth with hyperaemia of 
the pulp. It is tolerated in both of these conditions better 
than any other filling material, and, if well put in, will gen- 
erally stand long enough to accomplish good results. But 
to do well in either of these classes of cases, it must be 
made to cohere to the walls of the cavity. Otherwise it is 
liable on account of its softness to slight movement in the 
cavity, and to admit moisture. In that case the condition, 
especially of sensitive dentin, is liable to be made worse in- 
stead of better. 

Exposure and Removal of the Dental Pulp. 

Exposure of the dental pulp. — The pulp of a tooth may 
be found exposed by caries so that it lies naked and in 
view ; it may have been reached by the extension of caries 
but remain covered by a softened carious mass of dentin ; 
it may become exposed by accident during the preparation 
of a carious cavity; the conditions may require that an 
intentional exposure be made through a carious cavity that 
has nearly reached the pulp, or that an intentional exposure 
be made, there being no carious cavity. 

The first and second cases are so similar that they may 
12 



1/8 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

be treated of together, only noticing differences of manipu- 
lation as they occur. In both, the supposition is that the 
pulp is to be destroyed and removed. In the first procedure 
the problem is the preparation of the cavity for the treat- 
ment of the exposed pulp, and with the least pain and in- 
convenience to the patient. 

The requirement is that the cavity be opened by the 
removal of all overhanging enamel and that the surround- 
ing walls be freed from carious material, perfectly cleaned 
to solid dentin, and cut to a form that will certainly retain 
a temporary filling for the purpose of sealing in applica- 
tions that may be required in the treatment of the pulp. 
It is not required here that the cavity be cut to the full 
outline form, as it will be prepared to receive the perma- 
nent filling later; nor that permanent anchorages be 
provided ; but it is required that good and sufficient anchor- 
age be provided for a temporary gutta-percha filling against 
good, clean surrounding walls in every part. It should be 
opened sufficiently wide to admit of the free and easy 
application of instruments for the exposure of the pulp. In 
doing this especial care should be taken, that the instru- 
ments used be not directed toward the pulp of the tooth 
and that it be not interfered with in any way until after 
the surrounding walls are clean and solid in every direction. 
This excavation is to be done upon the principles already 
laid down for the excavation of cavities in the class to 
which the case in hand belongs. If the rubber dam has not 
been placed at the beginning, it should be placed now and 
every preparation made for the best possible view of the 
deeper parts of the cavity. The next step is the removal of 
the carious material from the deeper parts of the cavity — 
the axial or pulpal wall — and from about the exposure. In 
case the exposure is large and the pulp is already laid bare, 
this need not be very perfectly done at first, the necessity 
being that applications can be laid directly upon the pulp 
tissue and perfectly sealed in place by a temporary filling. 
In case the pulp is covered with carious material only this 
should be removed and the tissue of the pulp laid bare. 
In every position this should be done with the broadest cut- 
ting instrument that is applicable to the position, usually 



EXPOSURE AND REMOVAL OF THE DENTAL PULP. 179 

with the spoons. One should never undertake to remove 
softened material from over a pulp with an instrument so 
small that it is liable to penetrate through the opening into 
the pulp chamber, lacerate the pulp tissue, and inflict un- 
necessary pain. This should be taken as a principle con- 
trolling every procedure in this class of cases, and the 
operator should see to it particularly that the cavity be so 
opened and prepared that broad points may be used with 
facility. When these preparations have been made, if the 
case be other than a proximate cavity in the incisors, take 
the spoon 20-9-12, and having determined the best direction 
in which to make a sweeping cut, start its edge carefully 
under the carious mass close against one of the walls of 
the cavity and, with a strong thrust in a curved direction, 
carry it across the other side, cutting at once to the full 
depth of the softened dentin, and if possible remove the 
whole mass at the single cut, laying the pulp bare. This 
should be carefully planned and firmly executed. If the 
cut should be through the superficial portions of the pulp, 
excising a portion of the tissue, it is just as well, for when 
the hemorrhage has ceased we are sure of the best condi- 
tion for the absorption of remedies for destroying it, 
whether this be done by the application of the arsenic or 
by the use of cocaine under pressure. In some broad 
cavities in which it may seem that the carious mass is too 
broad to be removed at a single cut, one or more pre- 
paratory cuts may be made to either side, avoiding the 
pulp, before making the principal cut for its exposure. 

An exposure of the pulp made in this way is usually not 
very painful, and even if it be very sensitive, the duration 
of the pain is reduced to the shortest limit. 

In proximate cavities in the incisors the spoons 20-9-12 
can not generally be used for want of room. Much oftener 
the spoons 15-8-12 or the discoid are applicable. In these 
cavities the most desirable direction for the final cut for 
exposing the pulp is from the gingival toward the incisal 
directly over the pulp. In these cases the opening into the 
pulp is apt to be long inciso-gingivally, and if the broad 
cutting edge can be placed at right angles to this it is much 
safer against dropping into the pulp chamber and produc- 



l8o THE TECHNICAL PROCEDURES IX FILLING TEETH. 

ing unnecessary laceration of the sensitive tissues. By 
proceeding carefully this position or an angle closely proxi- 
mating it can often be obtained, and then the exposure is 
made with safety: a discoid 15 is really the best instru- 
ment for the purpose in this position. By working with 
care the exposure may be made with hatchet 12-5-12, cut- 
ting from labial to lingual, but with much more danger of 
inflicting severe pain. 

Destroying the dental pulp. — When the pulp has been 
fully exposed, the cavity should be ready for the applica- 
tion to the pulp without further preparation. If it is to be 
destroyed by arsenic, cut a piece of ordinary writing paper 
of such size and form that it may be easily so laid in the 
cavity as to cover the exposure, and try it in place. Then 
the walls of the cavity should be moistened with eucalyptol 
or oil of cajuput, to prepare them for receiving a gutta- 
percha filling, and any excess of oil removed. Then place 
a small, but sufficient, amount of arsenical paste upon this 
paper, and apply it directly to the exposure, and press it 
gently in place ; see to it carefully that there is not so much 
of the paste that it will run out around the margins of the 
paper, and be in danger of smearing the walls of the cavity, 
and possibly getting out toward the gingival margin of 
proximate cavities, for in this case there will be danger of 
arsenical poisoning of gum tissues. Place over this a 
gutta-percha filling, using especial care not to make un- 
necessary pressure over the exposure of the pulp that will 
cause compression and pain. This gutta-percha filling 
should be as perfect in its adaptation to the cavity walls 
as it is possible to make it, in order that there may be no 
leakage of the arsenic outward to poison the surrounding 
tissues, or of moisture from without inward to interfere 
with the action of the drug. Another important care 
should be that in proximate cavities no overplus of gutta- 
percha be allowed to infringe upon the gum septum and 
cause absorption. Overplus in this direction is readily 
avoided by placing any suitable instrument between the 
teeth at the gingival, such as the shaft of hoe 8-3-6, and 
making the gutta-percha filling against that, and afterward 
removing the instrument. This gives room for the gum 



EXPOSURE AND REMOVAL OF THE DENTAL PULP. l8l 

septum, and yet allows the temporary filling to be placed 
firmly against the proximating tooth. Finally, the filling 
must be so finished as not to give the patient annoyance, 
after which the patient may be discharged for forty-eight 
hours, or until the arsenic has acted. 

Anaesthetizing the dental pulp. — If it has been decided 
to anaesthetize the pulp with cocaine under pressure, the 
opening into the pulp must be free and large, and the posi- 
tion such that the after-manipulation can be readily done. 
The surrounding walls must be sufficient so that the drug 
may be readily confined under pressure, and the access 
fairly direct. Otherwise arsenic should be used. 

When the cavity has been fully prepared — an occlusal 
cavity in an upper first molar for example — a sufficient 
amount of cocaine crystals should be dissolved in a few 
drops of water in a capsule (always made fresh for each 
case), and a small pellet of cotton saturated with this 
solution is placed in the cavity upon the exposed pulp. 
Over this place a pellet of soft, or unvulcanized, vulcanite 
rubber that will completely fill the orifice of the cavity and. 
prevent the escape of the solution. Upon this make pres- 
sure with a broad-faced amalgam plugger. The pressure 
should be gentle at first, and be gradually increased as the 
pain is relieved, watching for evidence of pain in the coun- 
tenance of the patient, until very heavy pressure can be 
made. This should be maintained for several minutes. 
Then if all has gone well the rubber and the cotton may be 
removed, and the pulp will be found insensible and its 
removal may be proceeded with.* 

In anaesthetizing the pulp in this way notice particularly 
that the cavity must be so stopped with the soft rubber as 
to prevent the escape of the solution along the cavity 
walls, otherwise the pressure will fail to force the drug into 
the pulp tissue and the anaesthesia will fail. This is fairly 
easy of accomplishment in the cavity named above and 
those of similar form and situation. But in proximate 
cavities it is often much more difficult to so place the rub- 
ber that it will successfully stop the orifice of the cavity 
and prevent the escape of the fluid. In the molars and 



Prof. A. H. Peck's Lectures, 1899. 



l82 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

bicuspids this may be successfully done by first placing a 
properly formed piece of rubber against the proximating 
surface of the adjacent tooth and forcing it against the 
gingival wall of the cavity, and then doubling it over the 
occlusal portion so as to close that also, and then applying 
pressure with a broad instrument point selected to fit the 
cavity to the best advantage. As one becomes expert in 
this, most cavities may be so handled as to successfully 
produce anaesthesia of the pulp. 

Opening the pulp chamber preparatory to removal of 
the pulp. — When the pulp has been destroyed by arsenic, 
the procedure when the patient has returned for the next 
sitting is first to adjust the rubber dam. In proximate 
cavities in which the gutta-percha filling has been placed 
firmly against the proximating tooth, the filling must first 
be cut through with a Kceber saw, or trimmed away with 
a sharp finishing knife in order to allow the rubber dam to 
pass. When the dam is in position sterilize the field of 
operation by mopping the teeth included, their interproxi- 
mate spaces and the adjacent rubber with 1-2-3, oil of 
cloves or oil of cassia, and then drying them off with 
absorbent cotton. Then the gutta-percha filling may be 
softened by warming a burnisher and passing the hot point 
into it, and holding it for a moment to allow the general 
softening of the gutta-percha, when it may be lifted out. 

The cavity is now freed from the arsenic paste and 
washed out with the antiseptic and dried. It is now ready 
to proceed with the opening of the pulp chamber. In case 
the pulp has been anaesthetized with cocaine, the rubber 
dam will be in place and ready for the opening of the pulp 
chamber so that from this time the procedures in the two 
cases will be similar. In either case the pulp should first 
be pricked cautiously with a very fine broach, to be sure 
that it has lost its sensibility, for sometimes there is a 
failure in either way of operating. Having determined that 
the conditions are favorable for removal of the pulp, the 
first operation is the opening of the pulp chamber. In the 
bicuspids and molars this consists in the removal of the 
entire roof, or dentinal covering, and the manner of doing 
this will depend much upon the extent and the location of 
the decay. 



EXPOSURE AND REMOVAL OF THE DENTAL PULP. 183 

In occlusal cavities in the molars in which the decay is 
large, often the hoe 6-2-23 can be slipped into the opening 
and the roof of the chamber pulled away, uncovering the 
entire pulp. But when the dentinal covering is strong, as 
is usually the case when the opening is only the exposure 
of one of the horns of the pulp, the better way is to enlarge 
the opening with a small fissure bur. This is passed into 
the pulp chamber through the orifice of the exposure, and 
when the operator is sufficiently sure in his knowledge of 
the anatomy, he may cut around the pulp chamber parallel 
with its axial walls and remove the covering in a single 
piece. Otherwise the opening may be enlarged by carrying 
the bur laterally toward the central portion of the covering 
of the chamber and then carrying it around in a circle. 
Then hoe 6-2-23 may be passed into the opening and its 
blade turned under the roof covering the pulp, the over- 
hang determined, and the cutting directed, until the whole 
extent of the chamber is uncovered ; no overhang should 
be left at any point. In this cutting the greatest care 
should be taken that the bur be not pressed onto the floor 
of the chamber and its form marred by cutting into it. 
When the whole of the roof has been removed, it is gen- 
erally best to enlarge somewhat toward the mesio-buccal 
angle in order to better reach the mesio-buccal root canal. 
This may be done most readily and in the best form by a 
scraping movement with the cleoid. The case is now ready 
for the removal of the pulp. Incidentally much of the 
tissue of the bulb of the pulp, possibly all of it, will have 
been removed in doing this cutting, but no attempt should 
be made to remove the pulp from the canals until this 
cutting is satisfactorily completed, and the cavity cleared 
of all dentin chips and cuttings. If this is neglected it will 
often happen that these cuttings will get into the smaller 
root canals and so occlude them that they cannot again be 
opened. It is on this account that all cutting in opening 
the pulp chamber, especially in bicuspids and molars in 
which some of the canals are often very small, should be 
fully completed before any effort is made to remove the 
pulp from the canals. When in any case a mistake has 
been made in this and it is found that more cutting for 



184 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

access to some one root canal must be made a bit of cotton 
should be placed loosely in the root canals that have been 
opened, and remain while the cutting is being done, and 
until the cavity is again freed from cuttings. Then with 
the removal of this cotton the last of the cuttings will be 
removed. 

In many cases after the first opening has been made the 
roof of the pulp chamber can be cut away quicker and 
much more satisfactorily with the chisel and mallet. 

If the exposure is from a mesial cavity the cutting will 
be, of course, to the distal and often will involve the re- 
moval of the middle third of the occlusal surface with the 
whole of the dentin intervening between it and the pulp. If 
a distal cavity, the middle third bucco-lingually of the 
occlusal surface with the intervening dentin should at once 
be removed to a point well toward the mesial marginal 
ridge. 

In the bicuspids the exposures are almost uniformly 
from cavities in the proximate surfaces, and the chambers 
are broad bucco-lingually. The cutting for the opening of 
the chambers must be directed first to the central part of 
the crown, but later broadened from buccal to lingual ; for 
the horns of the pulp, when long, in these teeth spread out 
toward the points of the cusps. These should be fully 
opened into so that they may be cleaned, also the root 
canals in these teeth, especially in upper first bicuspids, arc 
given or! from the extreme buccal and extreme lingual 
portions of the chamber, and unless this cutting is broad in 
this direction, the broach will not have direct entrance into 
them. 

In the incisors and cuspids exposures are generally from 
proximate cavities. In opening these for the removal of 
the pulp, the orifice of the exposure should be first extended 
to the gingival wall of the cavity, and to the full breadth 
of the chamber. The approach should be carefully consid- 
ered. Generally a broach will not readily slide into the 
canal without being bent more or less. This is unfavorable, 
and a better approach must be made. Generally when a 
cavity is so large that the pulp has been reached, the 
lingual wall should be cut away, and this will improve the 



EXPOSURE AND REMOVAL OF THE. DENTAL PULP. 185 

approach, the instrument being passed to the lingual of the 
incisal edge of the tooth ; rarely the labial wall should be 
cut away. Then, to improve the approach still more, take 
a small fissure bur in the engine, and approaching the canal 
from the direction in which a broach would be introduced, 
pass it into the canal, and cut by lateral pressure, broaden- 
ing the canal in a direction to straighten the approach. 
This cutting will be toward the disto-lingual if a distal 
cavity, or mesio-lingual if a mesial cavity, if the approach 
is to the lingual of the incisal edge. 'From whatever the 
direction of the approach, the cutting is to be so directed 
that the broadening" of the coronal portion of the canal will 
straighten it. In this cutting special care should be had 
that the end of the bur should not cut the opposite side of 
the canal and roughen it, for if it should, the point of an 
instrument will be catching in the rough points at every 
effort to introduce it into the canal. By this cutting the 
curve of the instruments introduced into the canal for the 
removal of the pulp, or for filling the canal, will be much 
less abrupt, and these operations can be done more per- 
fectly. 

It is particularly desirable that all cutting in opening 
the pulp chamber be completed and the cavity cleaned of 
chips or cuttings before the pulp is removed from the root 
canals. Often these cuttings will fall into a small canal, 
and an instrument thrust will so fasten them as to occlude 
the canal. If in any case it should become necessary to do 
more cutting after removing the pulp from one root canal 
in order to gain access to another, a wisp of cotton to catch 
any chips should first be placed in the open canal. 

Removal of the Pulp. 

The instruments used for removing the pulp from the 
canals are the barbed broach and the smooth broach. Gen- 
erally the barbed broach should be used first. Usually the 
bulb of the pulp will have been removed during the open- 
ing of the pulp chamber, and the broach selected should be 
suited in size to the canal. Test the broach before usino- 
it by taking the point on the finger and bending it. See 
that it bends in a regular curve. Occasionally in cutting 



l86 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

the barbs the shaft is cut too deeply at some point, which 
will cause it to break easily — such a broach should be dis- 
carded. The broach should be held in a light handle, but 
may be used without. Just before introducing the broach 
dip it into a good antiseptic, preferably 1-2-3, or oil of 
cloves. This should never be neglected, for the broaches 
are liable to carry micro-organisms into the canal and infect 
it. Xow pass the broach into the canal, directing it 
against one of the walls., so that it will pass in beside the 
pulp tissue rather than through it. Generally the point 
should be pushed to the apical foramen and then, if it is felt 
to be held tightly in the apical end of the canal, withdraw 
it until it is felt to be loose. Xow rotate the broach lightly, 
moving it slightly back and forth to be sure that the whole 
length is rotating and not being held in some curved part 
of the canal which should be liable to break the broach. 
The rotation should not exceed one turn, then withdraw it. 
In a good many cases the entire contents of the canal will 
be brought away with the first effort. If not, the move- 
ment is repeated. Often the tissue of the pulp will break 
up into shreds and be but partially removed. In this case 
the smooth broach with cotton should be used. For pre- 
paring this the fingers should be disinfected by taking a bit 
of cotton moistened with the disinfecting agent used, and 
rolling it between the fingers and thumb. Then take a 
small bit of absorbent cotton and pull it between the fingers 
of the two hands until a small shred is formed containing 
but a few parallel fibers. Take one end of this between the 
forefinger and thumb of the right hand and grasp with it 
the broach at midlength, or with the cotton wisp extending 
slightly past its point. With the left hand grasp the other 
end of the cotton wisp and the point of the broach together 
and rotate the broach in the fingers of the right hand until 
the cotton is wrapped firmly upon its shaft. When this is 
properly done the cotton will cling firmly to the broach, 
and is not likely to be lost in the canal. With the broach 
thus armed, dip it first in the antiseptic and then pass it 
into the canal, slightly rotating back and forth. When 
the full depth has been reached, turn the broach fully upon 
its axis and withdraw it while in rotation. Generally the 



EXPOSURE AND REMOVAL OF THE DENTAL PULP. 187 

shreds of the pulp will become entangled in the cotton and 
be brought away. This should be repeated until satisfied 
that all tissue has been removed from the canal to the apex. 

Students often have difficulty in finding the canals in 
the molar teeth. Specific directions for approaching them 
are given in the anatomy.* Difficulty of this kind should 
not occur except in abnormal cases, and when they do, it 
is generally because the floors of the pulp chambers have 
been multilated with burs, and the openings of the canals 
filled with chips. This should never be done ; burs should 
not be used in the floor of the pulp chamber. 

No specific directions can be given for abnormal cases. 
When the pulp chamber is filled with secondary deposits, 
the effort should be directed to the removal of these, pre- 
serving the outlines of the pulp chamber. When the pulp 
chamber is much narrowed by secondary dentin deposited 
upon its walls, the openings into the canals should be found 
before any cutting is done, and then the cutting carefully 
directed to straightening them. In most instances this is 
done best with the barbed broach. All small tortuous 
canals should be enlarged and straightened with the barbed 
broach. To do this, cause the broach to enter the canal 
as far as possible and withdraw it. The barbs will impinge 
upon the walls and cut away the dentin. Repeat this, 
pressing the broach in a direction that will tend to 
straighten the canal. By repetitions of the movement, the 
canal that can be entered by the smallest broach can soon 
be enlarged sufficiently for filling. Generally partial occlu- 
sions of canals are confined to or near their pulpal ends, 
and where this has been straightened up, the broach will 
pass to the apex. In elderly people certain canals are often 
too small for successful cleaning and filling. In cases in 
which there has been much wearing away of the teeth, the 
pulp chambers and the pulpal ends of the root canals are 
apt to be much narrowed by secondary dentin. This applies 
to all of the teeth in the mouth, i. e., to any that have, from 
any cause, not been worn away the same as those that are 
worn. 

When the root canals have been cleaned, it is generally 

*Black's Dental Anatomy. For upper molars, paragraphs 173 to 178 inclusive; for 
lower molars, paragraphs 180 to 185 inclusive, to which the reader is referred. 



l88 THE TECHNICAL PROCEDURES IX FILLING TEETH. 

necessary that a dressing be laid in the canals and the 
cavity sealed with a gutta-percha rilling until a future time. 
For this purpose a wisp of cotton should be formed with 
its fibers mostly parallel, and the end of this caught with 
the point of the broach with the thumb and finger of the 
left hand and the broach rotated with the right hand, while 
the fingers of the left roll the cotton on its end. In this 
way the cotton is rolled on the broach in such a way that 
it will not slip backward on the broach and can be carried 
to the apical end of the canal ; and when the broach is 
withdrawn the cotton will remain in the canal. This is 
now saturated with the dressing, or drug indicated, and 
laid in the canal. One end of the cotton wisp should 
project into the pulp chamber in order that it may readily 
be removed at another sitting, and the cavity sealed with 
a gutta-percha filling. 

Rule : In no case should the saliva be allowed to enter 
a root canal after the pulp has been removed. At any 
future sitting the rubber dam must be applied and the in- 
cluded region disinfected before the gutta-percha filling is 
removed. Any neglect of this precaution is apt to result in 
alveolar abscess. 

In cases of dead pulps, pulps in a state of decomposition, 
empty root canals, alveolar abscesses, etc., the technical 
processes of cleaning the canals are not essentially different 
from those described, though they may require radically 
different medicinal treatment. This latter is not within the 
province of this book. 

Opening the Pulp Chamber in Sound Teeth. 

Frequently it is necessary to open the pulp chamber of 
teeth that are sound or have fillings previously inserted that 
it is not desirable to remove. The pulp may be dead or in 
such a condition of disease that it should be removed. In 
these cases it becomes necessary to cut from the surface of 
the tooth or through the filling. In case of the incisors or 
cuspids the best place to enter the pulp chamber is through 
the central portion of the lingual surface. For this purpose 
a bibeveled drill, one millimeter in diameter, should be first 
used. With this the enamel should be penetrated and the 



EXPOSURE AND REMOVAL OF THE DENTAL PULP. 189 

drill forced a little distance into the dentin. Then this 
opening should be considerably enlarged by a larger drill 
or a round bur. Then the small drill should be forced 
carefully into the pulp chamber. If the pulp is alive and 
sensitive, it should now be destroyed. Afterward the com- 
plete opening of the chamber may be proceeded with. If 
the pulp is dead, the further opening of the chamber may be 
done at once. 

In cutting into the pulp chamber the drill has entered 
from the lingual at a considerable inclination, and it is now 
necessary to make the opening as near parallel with the 
length of the pulp canal as practicable. To do this use a 
fissure bur, pass its end into the pulp chamber and bring 
the hand-piece slowly parallel with the long axis of the 
tooth, cutting mostly from the incisal wall of the opening 
first made, but also cutting some from the distal wall of the 
pulp chamber. This cutting should be sufficient to admit 
a broach to the full length of the canal, with very little 
bending. The cleaning and treatment of the canal can then 
be proceeded with. 

Generally, when incisors have proximate fillings that 
are good, the opening into the pulp should be made from 
the lingual, without disturbing the fillings. If, however, 
there is reason for removing a proximate filling, the pulp 
chamber should be opened through the cavity. 

In case of bicuspids and molars the opening should be 
made through the occlusal surface. In bicuspids the mesial 
pit should be chosen. In molars it is generally much easier 
to penetrate the enamel through the pit in the central fossa. 
In this case, as soon as the dentin has been entered, it is 
best to introduce a small inverted cone bur, and cut a slot 
to the mesial, inclining to the buccal, as far as the mesial 
marginal ridge, and chip the enamel from its margins. The 
length of this toward the mesial will depend on the position 
of the tooth and the inclination of the hand-piece in drilling 
through the dentin. The dentin is thick, and in passing 
through it, this inclination will often carry the hole con- 
siderably to the distal. Therefore, in beginning again with 
the drill it should be set sufficiently to the mesial so that 
it will strike the pulp chamber centrally, or to the mesial 



I90 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

of its center. In drilling through the dentin the. small drill 
(one millimeter in diameter) should first be made to pene- 
trate a little, and then the hole enlarged, then drilled deeper 
and enlarged, until the dentin has been cut through. If 
the pulp is alive and sensitive, it should now be destroyed ; 
if dead, the opening may at once be so enlarged as to 
remove the entire roof of the pulp chamber, and the treat- 
ment of the canals proceeded with. Never undertake to 
treat pulp canals through a little bit of an opening. 

In a considerable number of cases it is necessary to 
open the pulp chambers of bicuspid and molar teeth that 
have been filled. If the fillings are good, proceed as if the 
tooth was sound, cutting through the filling, or through the 
dentin, as the case demands. If there is reason for remov- 
ing the filling, do so at once, and open the pulp chamber 
through the cavity. 

Filling Root Canals. 

When it is decided that the conditions are right for 
filling the root canal, or canals of a tooth, the rubber dam 
must be placed and the included region disinfected. Then 
if a treatment has been in the canal the gutta-percha filling 
and the dressing is removed and a critical examination 
made as to its condition. If this is satisfactory, first see 
that the canal is reasonably dry, then flood it with 
eucalyptol or oil of cajuput, liberally applied upon a wisp 
of cotton wrapped upon a broach, and dry out the excess 
with a fresh wisp of cotton that has first been dipped in 
the oil and well squeezed out with another wisp of cotton. 
Try the sizes of the root canal pluggers in the canal, 
always washing the point with an antiseptic first, and select 
one that will pass nearly, but not quite, to the apical fora- 
men. Select a gutta-percha cone and cut a portion of it 
about three or four millimeters long of the size which, from 
the information gained of the size of the apical end of the 
canal, will be sufficient to fully fill the opening and not 
force through the apical end. Warm the point of the root 
plugger selected, and holding the piece of gutta-percha 
cone in the thumb and finger of the left hand, bring its 
point quickly in contact with its large end, and hold it a 



FILLING ROOT CANALS. I9I 

moment, or until the gutta-percha has stuck to the end of 
the instrument. Dip this into eucalyptol, which will soften 
the surface of the gutta-percha slightly; convey this to 
the root canal and start it in carefully, and carry it firmly 
into its apical end. On withdrawing the root plugger the 
gutta-percha cone will remain, closing the apical end of the 
root. Repeat this with other bits of gutta-percha cones ; 
~ut them from larger parts of the cones as the canal is 
filled to its larger portion and use the larger root canal 
plugger. After the first two or three pieces the subsequent 
ones may be slightly softened by passing them quickly over 
the flame of the annealing lamp and directly into the canal. 
Continue this until the canal is full. 

This plan of filling root canals is applicable to ali except 
the very smallest, and to all positions. In some of the 
smaller ones it is necessary to make a special root canal 
plugger for the case by cutting off the barbed portion of a 
Donaldson broach of a suitable size and squaring its end 
on the stone. 

Rationale of this procedure. — By flooding the root canal 
with eucalyptol or oil of cajuput the moisture is effectually 
removed. The oils have a greater affinity or attraction for 
the dentin than the moisture and displace it. In practice 
this is a much better method than drying with hot air or 
hot instruments. The drying is done much more perfectly, 
and is done much easier. These oils dissolve gutta-percha 
slightly, and the little remaining serves to stick the gutta- 
percha firmly to the walls of the canal. By putting in the 
gutta-percha in small pieces an opportunity is given to pack 
every portion. of the canal and all of its irregularities full. 

In filling root canals that are very large at the apical 
end, as in young persons, care must be exercised that the 
first cone belected is not so small that it could be forced 
through into the apical space. In very small canals, in 
which there is much doubt of being able to reach the apical 
end, chloro-percha* should be pumped into them, filling 
them as completely as possible, and then a small solid cone 
forced in. This pumping in of chloro-percha is done by 
wrapping three or four fibers of cotton firmly on a small 

'Gutta-percha dissolved in chloroform. 



192 THE TECHNICAL PROCEDURES IN FILLING TEETH. 

broach, dipping this in the chloro-percha and conveying it 
into the canal and pumping it back and forth, repeating the 
operation until the canal seems to be well filled. Then 
thrust a root canal plugger of suitable size into it and force 
out some of the gutta-percha from the pulpal end. Then, 
having a suitable gutta-percha cone prepared, quickly stick 
it onto the plugger point, and thrust it as far into the canal 
as possible. Such canals may not always be perfectly filled 
by this plan, or by any other. But in each case the best 
effort should be made. The pulp chamber should not be 
filled with gutta-percha. This material is much too soft 
to serve as a seat for a metallic filling. In any case in 
which it is not desirable to fill the pulp chamber with the 
material with which the cavity is to be filled, oxy-phosphate 
of zinc should be used. 

Horns of pulp chambers. — Attention to the horns of 
pulp chambers is most urgently demanded in the incisors, 
cuspids and bicuspids. In incisors particularly, exposures 
of the pulp, whether made primarily by caries, or by cutting 
into them, are some distance from the incisal end of the 
pulp, leaving an end protruding into the incisal end of the 
crown of the tooth. Before filling the cavity this must be 
looked for and so exposed that every part of it is cleaned 
and filled. Any neglect in this will result in discoloration of 
the tooth by the decomposition of the debris left in this 
neglected portion of the pulp chamber. In cuspids and 
bicuspids the horns of the pulp are often long and slender, 
and penetrate far toward the ends of the cusps. Unless 
these are thought of, and especially looked for and cut out, 
so that they may be perfectly filled, discoloration of the 
tooth in some degree is sure to occur. 



INDEX 



PAGE. 

Amalgam ■' • • 120 

cautions 168 

tilling with 164 

instruments for filling with 169 

" kneading of 166 

" packing, fillings 167 

preparing for filling with 166 

Amalgam fillings, discoloration of 164 

" finishing 169 

" " importance of separating teeth for 165 

" " placing matrix for 165 

" " removing matrix from 170 

" " where admissible 164 

Annealing gold 124 

Application of force in filling with gold '. 128 

Bite, strength of the 141 

Burs in cutting out grooves 40 

in cutting seats and steps 39 

" in making extensions for prevention 41 

" in making starting points for packing gold 42 

" in squaring out angles of cavities 40 

Cavities, beveling cavo-surface angle of 25 

" classification of 9 

" convenience form of 24 

" distal, in lower bicuspids, preparation of Ill 

filling distal, in bicuspids and molars 138 

" filling proximate, in incisors 139 

gingival wall, in proximate 137 

" in incisors and cuspids, general observations on the prepara- 
tion of 96 

" in proximate surfaces in bicuspids and molars, preparation of. 104 

" nomenclature of angles of 14 

nomenclature of internal parts of 10 

opening, in bicuspids and molars 105 

outline form of 21 

" proximate, in bicuspids and molars, filling with combination of 

non-cohesive and cohesive gold 139 

" removing carious dentin from 25 

" resistance form of 23 

retention form of 24 

variations in preparation of, due to position 109 

Cavity nomenclature 6 

nomenclature, rule for 6 

" preparation, general principles of 21 

preparation defined 6 

toilet of 26 

walls, management of weak, in bicuspids and molars 114 

Cement, filling with 174 

Cements 170 

examination of pbvsical properties of 171 

for inlays 162, 172, 174 

" how mixed 171 

" not impervious to moisture 172 

" shrinkage of 172 

" solvent action of oral secretions on : . . . . 173 

use of 1 73 

Clamps, rubber dam 56 

Classification of cavities 9 

Contra-angle hand-piece 40 

Cotton, wrapping on broach 186, 188 

Cutting out angles of cavities, use of burs in . 40 

193 
13 



194 INDEX. 

PAGE. 

Cutting out grooves, use of burs iu 40 

Cutting seats and steps, use of burs in 39 

Cutting, size of burs for 38 

Dental engine, use of 38 

Dental instrument gauge 30 

Divisions of the surfaces of the teeth in cavity description 20 

Drills, use of 42 

Enamel 58 

histological characters of. in relation to preparation of cavicies. . 59 

" margins, nomenclature of IS 

rods, how to study the inclinations of 66 

rods, inclinations of 61 

walls, finishing 25 

Excavation of cavities by classes 68 

Class first 68 

" " for inlays 77 

" " variations in 71 

" second 80 

for inlays 84, 88 

" " variations in 89, 90 

" third 91 

" " for inlays 98 

general observations on 96 

" fourth 101 

" after removing pulp 103 

for inlays 104 

variations in 102 

" fifth 104 

for inlays Ill 

" " variations in 109 

Excavation of cavities, order of procedure in 21 

Exposure and removal of the dental pulp 177 

Extension for prevention 9. 22, S2, 92 

in bicuspids and molars 107 

" " " use of burs in making 41 

Filling materials 119 

Filling root canals 190 

" '• rationale of procedure in 191 

" " " with large apical opening 191 

Filling, starting cohesive gold 134 

with amalgam 164 

with cement 174 

" with cohesive gold 128 

with gold 126 

with gutta-percha 175 

with non-cohesive gold 126 

Finishing fillings 147 

" " buccal and lingual embrasures 150 

" gutta-percha 176 

" in buccal and labial cavities 148 

" in occlusal, buccal and lingual cavities 148 

" " obtaining roundness of contact point 151 

" " overtrimming gingival margin in 148 

" " proximate 1 4*. » 

" " use of burnisher in 149 

" use of corundum stones in 148 

" use of disks in 151 

use of rubber disks in 149 

" use of tape in 151 

with file-cut finishing files 150 

Force, direction of. to plane of walls in packing gold 135 

Forms of plugger points 132 

Forms of shanks of plugger points 132 

Gnathodynamometer 142 

Gold 119 

" annealing 124 

" condensation of gases on I 22 

" destroying and restoring welding property of 123 

" filling with 126 

" forms of 121 

" the wedging principle 136 

. " welding property <>i' 122 

Grasps, rubber-dam 48 

Gutta-percha 175 

filling with * 175 

tinisliiiiL: fillings <>f 176 

us., of eucalyptol in filling with 175 



INDEX. 195 

PAGH. 

Incisal step ....:. 101 

Inclination of cavity walls 19 

Instruments and instrumentation 27 

Instruments for packing amalgam 169 

Instrument grasps 35 

Introduction . 5 

Ligatures, use of 52 

Making starting points for packing gold 42 

Management of weak cavity walls in bicuspids and molars 114 

Matrix, how to place 165 

removal from amalgam fillings 170 

Nomenclature 5 

cavity 6 

instrument 27 

of angles of cavities 14 

,; of cutting instruments 27 

of enamel margins 18 

of internal parts of cavities 10 

Order of procedure in cavity preparation 21 

Perry separator 116 

Perry separator, universal 117 

Phagodynamonieter 143 

Pit "cavities 7 

Planes of the teeth 19 

Plugger points, forms of , 132 

Plugger, forms of shanks of 132 

list of, required 133 

stepping of point of 136 

Polishing fillings 149, 151, 170 

proximate fillings 151 

Porcelain inlays 151 

" cement for 162 

" furnaces for 161 

" making of 158 

" matrix for 155 

" preparation of cavities 77, 84, 88, 98, 104, 111 

" selection of cases for 151 

" setting of 162 

Pulp, anaesthetizing the 181 

" destroying the 180 

" destroying the, with arsenic 180 

" exposing the '. 178 

'• exposure and removal of the 177 

instruments for removing the 185 

preparation of cavity for exposure of the 178 

" removal of the 185 

" removing the, from root canals 185 

Pulp chamber, horns of the 192 

opening the 182 

" in bicuspids 184 

" in bicuspids and molars that have been filled. . 189 

" in distal cavities in molars 184 

" in incisors and cuspids 184 

" in mesial cavities in molars 184 

" in occlusal cavities in molars 183 

" in sound teeth 188 

Relation of the size of plugger points to the application of force 130 

Root canals, filling 190 

" " finding 187 

" rationale of procedures in filling 191 

" " removing pulp from 185 

Rubber dam 46 

applying the 47 

" clamps 56 

" " grasps 48 

first 48 

" " second 49 

third 49 

fourth 50 

fifth 50 

" " ligatures in adjusting the 52 

Rule for extension for prevention in bicuspids and molars 107 

Rules for naming angles of cavities 14 

cavities , 6 

walls of cavities 11 

Separating irregular teeth 118 



196 



INDEX. 



PAGE. 

Separating teeth 11*3 

use of gutta-percha in IIS 

:' wood in 11 'j 

Sharpening instruments 

Smooth-surface cavities B 

Strength of the bite 141 

instruments for measuring the 141 

" " " measuring the 141 

L'se of the dental engine 

• drills 42 

" gutta-percha in separating teeth US 

■• ligatures 

'■ water 43 

" wood in separating teeth . . „ 110 

Water, use of 43 

Welding property of gold i 22 



7 1903 






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IF 



LIBRARY OF CONGRESS 




0DD5tDT7nfl 



